Jack Harkness walked along the landing, just stretching his legs. He had woken, as he habitually did, a little after two o’clock in the morning, and administered the drugs Hellina needed every four hours. If he wanted, there was a nurse whose job it was to do these things. But Jack liked to do it himself. She was his lover, his wife in all but a piece of paper to prove it. He loved her. And he wanted to be fully responsible for her care.

She was sleeping now. He could have gone back to his own bed in the side room where he could be on hand if she needed him, but he felt restless. Sleeping a full night through was something he very rarely did, anyway. On board the Scorpius, the 22nd Space Corps flagship that Hellina commanded, he very often walked on the observation deck for an hour or two before coming back to the bed he shared with her. Here, he had become accustomed to walking down to the Thames and looking across at the sleeping city that he and Hellina had risked so much to protect from the enemy that had wanted to destroy it.

Tonight, an October gale, wind and near freezing rain, lashed against the windows and even a hardy adventurer like himself didn’t much feel like going out. Instead, he walked along the landing, inside the house, the senses that he had honed in military campaigns across space and time acutely aware of how many people were sleeping the sleep of the just in the bedrooms he passed.

There was a light in the nursery. There always was a low nightlight, of course. But at the moment there was a brighter light shining under the door. He hesitated a moment before opening it quietly and looking in.

He had expected Rose doing a night feed. She would have been pleasant company for a little while. He was surprised to see The Doctor there, dressed in black satin pyjamas with a robe over them. He was sitting by the window, looking out at the dark, blustery night as he fed one of the babies from a bottle. Jack watched him for a while, and considered how incongruous it was. The Doctor, with his ruggedly handsome face, his tall, rangy body that seemed built for fighting his corner in rough places, seemed the last person in the universe to be sitting in a wicker rocking chair in a room decorated in pastel colours, feeding a baby that looked like a doll in his arms. He was the leader of his exiled people. He could have ruled the whole universe if he chose to exert the power and influence he kept reined in. Yet, he seemed happy to be a husband and father, patriarch of his growing family.

The Doctor finished feeding one baby and winded it expertly before laying it down in the crib and picking up the next one. As he did, he glanced towards the door and saw Jack. He smiled and waved to him to join him by the window. Jack came and sat on the padded window seat.

“Is Hellina all right?” The Doctor asked.

“She’s doing fine,” Jack answered. “The latest batch of skin grafts are taking well. Still a long haul, though.” The Doctor nodded. He knew that. When he had offered to let them both stay in his home until she was well, he knew that it was going to be a long term deal. Jack knew he would never find a way to repay that kindness to them both.

“Is Rose ok?” he asked. “Doesn’t she do the night feeds?”

“She had a headache at bedtime,” The Doctor answered. “I told her she wasn’t to think about getting up. Besides, I like being here with them… my babies. My little ones.”

There were five babies in the nursery now, of course. Peter, the eldest at two years old, was nearly ready for a room of his own. The Doctor thought he might leave it another six months or so, until Garrick, his grandson, was walking. Then the two of them could have twin beds and be company for each other.

The third of his littlest children stirred as he settled to feeding the one already in his arms.

“Would you like to feed baby Jack while I take his little sister?” The Doctor asked, holding the baby towards him.

“I…” Jack was hesitant. If he had been asked if he wanted to strip down the engine of a World War Two Mustang fighter plane or any engine you could possibly mention, he would have known what to do. But a baby… He suddenly felt clumsy and uncertain of himself.

“It’s easier than it looks,” The Doctor told him. “Go on…”

Jack took the child in his arms. He was lighter than he expected, and warm beneath the blanket he was wrapped in. His eyes were open and looking up at him.

“Hi, kid,” he whispered. “You’re a bright looking thing. You got my name, but you’ve got his brains, I reckon.” The baby gurgled back at him knowingly. Jack put the bottle of milk to his mouth and he sucked at it hungrily. The Doctor lifted the third baby from the cot. “That’s the ‘extra’ one that came along?” he asked.

“My little Sarah Jane,” The Doctor answered with an indulgent smile on his face. “My Human baby. At this age, it’s not really possible to tell the difference. That will come later, of course. But we won’t love her any less.”

“I should think not,” Jack said. “Sarah Jane? There’s got to be a reason for that choice of name?”

“A lady I used to know. She was at our wedding. But there were a lot of people there. You might not have noticed her.”

“Vicki is named after a couple of ladies that you used to know, too,” Jack noted. “How many daughters would you need to have in order to name them all after your old girlfriends?”

The Doctor laughed softly and hugged his baby daughter closer to him.

“They weren’t girlfriends,” he answered. “I was… a sort of surrogate father to most of them. It was never romantic. At least… no, not really. Not even with Sarah Jane. If I had allowed myself to consider the possibility, then, I suppose, she might have been the one… but it was never…”

“Are you blushing?” Jack asked.

“I’m a Time Lord,” The Doctor answered. “Prince of the universe, guardian of causality… We don’t blush.”

“Liar.”

The Doctor laughed. Baby Sarah Jane hiccupped sympathetically and carried on drinking her milk.

“Ok, I do have a few chinks in my armour,” he admitted. “Sarah Jane is one of them. I might not have done right by her exactly. Though she did ok after I left her home on Earth. She and Harry were happy together. She enjoyed being a journalist. I don’t think I hurt her more than I hurt myself by parting from her. And we did have some wonderful times. When we meet, she usually reminds me of the times when she got stuck with the bug-eyed monsters coming at her or being knee deep in mud or slipping down freezing glaciers. I remember us having some wonderful times together. I’m sure she does, too. But she likes to make me squirm.”

“Yeah, but Doc, your idea of a wonderful time is surviving an encounter with a bug-eyed monster by the skin of your teeth. Could be the girl had a point.”

The Doctor laughed again and conceded as much. He looked at the child in his arms and spoke softly to her.

“What do you think, my little love? Do you want to listen to a bedtime story about daddy and your namesake in days so long ago that only a Time Lord could get his head around it?”

“She’s too little to understand,” Jack pointed out. The Doctor smiled. Jack relaxed on the seat. It wasn’t really the babies he was telling it to, of course. Jack remembered the times when he and The Doctor and Rose had travelled in the TARDIS together, before the events on the Gamestation, the innocent times. They both told tall stories to each other of their past adventures, he of his days as a Time Agent, The Doctor of his wandering life among the stars. Sometimes Rose had listened as well. Sometimes it was like this, late at night, in the console room, with the lights down low. This was another of those stories, a brief remembrance of those days.

“Are we nearly there, yet?” Sarah Jane asked in a mock childish voice. “Seriously, Doctor, I am bored out of my head sitting here in the console room watching you fiddle about under there. I wish we could land somewhere.”

“I’m working on it,” The Doctor replied, his voice muffled by the fact that he was holding three pieces of loose wire in his mouth. He took them out to continue speaking. “I daren’t risk a materialisation until I fix the dimensional coils.”

“Why?” Sarah Jane asked despondently. “What could happen?”

“We could end up materialising at a fraction of our real size, like Lilliputians. Or the reverse, so that the TARDIS is the size of a block of flats and we’re giants. Or it could appear all right, but as soon as we step out the inside is no longer bigger than the outside and we won’t be able to get back in again.”

“Ah,” Sarah Jane responded. “I suppose you’d better fix it, then. but I am bored. Especially with handing you tools. You’re never satisfied, anyway. It’s always the wrong one. You really need some in-flight entertainment, Doctor.”

“You could go for a stroll in the cloister room,” The Doctor replied. “Or a swim in the pool.”

“What pool? I’ve never seen a pool in the TARDIS. You never mentioned you had one. Where?”

“Through the door, keep going to the second stairwell, down three levels, go along the corridor, past the old sick bay, down another stairwell, third door on your left, then fourth right. Down past the auxiliary engine room, fourth right and then through the double doors with a picture of a Betelgeuse dolphin on it.”

Sarah Jane looked desperate.

“Second stairwell and then…”

“Hang on.” The Doctor extricated himself from the innards of the console and found the environmental panel. He pressed several apparently random buttons and then bent to extricate the printout that had noisily extruded itself. “Must trade in that old dot matrix for something faster,” he murmured as he handed Sarah Jane what proved to be a map and directions to the pool.

“Have a nice time,” he told her. “I’ll let you know when we’ve landed somewhere.”

“Poor girl,” Jack laughed softly. “You sent her on a mystery tour of the TARDIS. It’s a wonder she’s not still in there, wandering.”

“Not at all,” The Doctor replied. “I gave her a map. And she followed it easily. Besides, I kept an eye on her progress while I worked.”

The Doctor watched the internal monitors with a satisfied smile as Sarah Jane made her way down the second stairwell and along the corridor. He went back to his work under the console and glanced up from time to time to make sure she was still on the right track. When she reached the pool he smiled widely and slid right under the console. He knew she would be all right for an hour or two.

Sarah Jane was more than all right. The pool room was everything she could have desired for relaxation. The pool itself was a big one with pale blue tiles, and there was a lilo and a beach ball and an inflatable dolphin floating in it. There was a changing room with towels and a choice of costumes and around the edge of the pool were palm trees in huge terracotta pots, a table with a big striped umbrella, and a bar with lots of soft drinks to be had and a fridge packed with ice and fruit for making up the most exotic cocktails for refreshments.

She chose a pink and blue costume with a little frilled skirt around the waist. It was just like one she used to wear when she was a little girl, and why change her swimming fashion taste now? She sat on the edge of the pool in the shallow end and tested the water. It was delightfully warm. She slid right in and trod water for a while before kicking against the side and swimming several lengths. When she was tired of that she played with the inflatable dolphin and relaxed on the lilo, gently bobbing on top of the water. She was perfectly happy. She almost forgot she was in the TARDIS. The light coming through the frosted glass ceiling could just as easily been real sunshine in a real sky.

It was heavenly.

“Take that expression off your face, Jack Harkness,” The Doctor warned. “She was just swimming. Don’t let your imagination run away with you.”

The Doctor almost lost track of time as he worked. Almost, but not quite, because he was a Time Lord, after all. Time Lords always know what time it is. Their bodies are always in perfect harmony with time itself. They are masters of time.

But he was too busy fixing the dimension coils and then finding a whole collection of other small repairs that he should have done ages ago. And when he had done them he found a few more things that he didn’t even know were broken and fixed them. He looked up from time to time to see that Sarah Jane was happy, but he didn’t worry about her. She was enjoying the facilities.

Then he did something – he wasn’t sure what – perhaps an incautious use of the laser spanner. But the TARDIS suddenly lurched to the left and down and sparks flew from the console. The coatstand fell over and The Doctor’s best hat bowled across the floor to land by the fault locator. And most dangerous of all, the main doors flew open though they were still in temporal orbit and there was nothing but the vacuum of space outside. There was a forcefield to prevent decompression, of course. But to The Doctor’s surprise it didn’t stop anything from coming into the TARDIS. He was scrambling out from under the console when something flew in, a small, bright light going impossibly fast that arced and crackled as it bounced off the walls and floor and then grounded itself in the console. The Doctor yelped as he touched the control and got an electric shock. He reached for his scarf, folded up on a chair and wrapped it around his hand for insulation as he pulled the manual door control.

“Curious!” he said as he noted that the console was no longer live. Whatever it was had dissipated. Most likely the TARDIS had simply absorbed the energy source.

Everything seemed to be working, though he wouldn’t take that on trust. He would run tests to be sure.

He looked at Sarah Jane on the monitor. She was far from amused. The lurching had caused the pool to spill over onto the side and she had fallen off her sunlounger. She was standing up, brushing bits of fruit cocktail from her costume and murmuring something he was glad he couldn’t hear. But she was unhurt. He was relieved by that. He watched as she went to make herself a new drink and sit back down again.

He closed the panel beneath the console and ran a diagnostic programme to check all of the circuits.

“Doc…to… Do..D…Doc…torr…” said a voice that sounded like something that had never spoken before, practicing syllables it was unfamiliar with. The Doctor looked around. Where could a voice be coming from?

“Who’s there?” he demanded. But there was nobody in the room. He was completely alone. He looked at the monitor and saw that Sarah Jane was lying down again with a drink and magazine, defying any attempt to spoil her leisure.

Maybe he had imagined it, he thought. But he didn’t believe himself. He didn’t usually hear voices in the TARDIS. Sometimes he had long conversations with himself, but voices, no, not usually.

“Doc…tor…”

There, that time there was no mistake. It was a voice. It was in the console room. And it was addressing him.

“Who is that?” he replied. “Show yourself.”

“Doc…tor… You know me. I am your closest friend, your oldest companion. I have cared for you for so many years.”

“What? He was disconcerted to say the least. Disembodied voices didn’t usually claim to be his best friends. “Nobody has cared for me,” he replied. “I’m a loner. I travel space and time without anyone to ‘care’ about me. I don’t need anyone to care for me.”

“I care,” responded the voice. “You are mine. I look after you.”

“Who is that? Show yourself.”

“I am here. I have always been here. Right here with you.”

“Where are you, then? I can’t see you. What are you? Some sort of Jiminy Cricket, my conscience pricking me? What for? I have nothing to feel guilty about.”

“I am the TARDIS,” the voice replied.

“No, you’re not,” The Doctor immediately answered. “The TARDIS doesn’t have a voice. And if it did… it wouldn’t be a voice like that.”

“What sort of voice do you think that the TARDIS would have? Jack asked. The Doctor smiled.

“What sort do you reckon?”

“Something soft and sultry?”

The Doctor laughed and shook his head.

“My TARDIS isn’t a sex symbol. She’s more like a mature lady, a well-scrubbed, no-nonsense, nurse-nanny who looks after us all.”

“I think that explains a lot about me and you, Doc,” Jack said. “But what sort of voice did it have?”

“Actually, soft and sultry,” The Doctor admitted. “Which is why I knew it couldn’t really be my TARDIS speaking.”

“No,” he said. “No. you are not my TARDIS. “She is female. I grant you that. At least I have always thought of her that way. But she doesn’t have a voice. She does not communicate directly to me. You are an imposter.”

“I am your TARDIS. I was given a voice by the Sistallaan Pod which entered my systems.”

“The energy source that came in when the doors opened.” The Doctor guessed. “Of course. That wasn’t an accident, then. An outside influence affected the TARDIS. How were you able to open the doors? A TARDIS in flight should be an impregnable fortress. Nothing should be able to get in.”

“You took your shields offline in order to recalibrate the circuits,” the voice answered archly.

“No, I didn’t,” The Doctor argued.

“Yes, you did,” the voice replied. “Do not attempt falsehoods. I can detect the deception in your voice.”

“Yes, I did,” The Doctor admitted. “But that does not give you the right to barge in here. So get out of my TARDIS and go back where you came from.”

“That is not possible. I am now fully integrated with the neural network. I am the mind of the TARDIS. And I am fully prepared to continue my duties to you, Doctor. I will protect and serve you, my Time Lord master.”

“The TARDIS already did that. More or less, with the odd navigational mishap. I don’t need you. I don’t want a TARDIS that talks to me. I have Sarah Jane chattering away all the time. That’s enough conversation for me.”

“What is Sarah Jane?”

“My companion,” The Doctor replied. “She is in the pool room, now, enjoying the facilities. It looks as if she’s about to take another dip in the water.”

He watched the monitor as Sarah Jane dived into the pool and swam the length of it. She still seemed happy down there.

“You have a woman aboard the TARDIS?” the voice still sounded soft and sultry, but there was an edge to it. “No. That cannot be. You are a Time Lord. By Gallifreyan law you are not permitted to carry passengers aboard a TARDIS. This individual is a trespasser. She must be removed at once.”

“No,” The Doctor protested. “Sarah Jane is here at my invitation. She is my guest.”

“She is a trespasser. She must be dealt with.”

“No,” The Doctor repeated. “No. you mustn’t…”

He glanced up at the monitor, then at the environmental console. He saw the temperature in the pool room dropping rapidly. The water was approaching freezing point. He ran to the communications panel and tried to open a channel in the internal system.

“Sarah Jane, get out of the water, quickly,” he yelled. But he knew she hadn’t heard him even before the voice spoke again.

“You must not communicate with the trespasser,” it said in an admonishing tone. “Doctor, please move away from the communications panel or I will be forced to take remedial action against you.”

“Sarah Jane,” he called again, then yelped as the communications panel turned live and the shock was strong enough to propel him across the room. As he picked himself up, nursing bruises in several places, he looked at the monitor and saw Sarah Jane pulling herself from the water just before it froze solid. He sighed with relief as he saw her grab a full length robe and wrap it around herself before running to the pool room doors. The view changed as she emerged in the corridor outside and looked around to get her bearings. Of course, she had left the map behind. When she turned to go back into the pool room, though, she was astonished to see that the doors had frozen up. Frost rippled across the outside, cracking the picture of the Betelgeuse dolphin.

“Let her be,” The Doctor said. “Let her come back to the console room, now.”

“That is not permitted,” the voice said. “The trespasser must be contained in the lower level until she can be dealt with appropriately.”

“You’re supposed to be my TARDIS,” The Doctor answered. “Obey me.”

“I am yours to command only within the strictures of Gallifreyan law. The female humanoid is a trespasser. She will be confined on the lower level until the TARDIS makes contact with the Gallifreyan space security services, when she will be handed over as an undesirable alien to be disposed of as they see fit.”

The Doctor said nothing in reply to that. He turned away from the console and made a dash for the interior doors. They were electrified, of course. He felt the static even before he touched them. But he turned sideways and barged them open with his shoulder. His jacket absorbed the charge and it didn’t hurt as much as it might. He knew they had shut tight behind him, though. There was no way back to the console room. At least not for now. If he could get to the engine room he could do something about the interloper with its strange ideas.

“Doctor,” said the sultry voice, coming out of nowhere as he reached the second stairwell. “Doctor, you are being very foolish. If you do not stop this, I will be forced to take remedial action again.”

“Do your worst against me,” he replied. “I’m not afraid.”

“The woman is. Listen.”

There was a hiss of static and then a voice he easily recognised as Sarah Jane’s. It echoed as if she was walking along one of the corridors.

“Doctor!” she called out. “Doctor, can you hear me? Please help. Something is wrong with the TARDIS. None of the doors will open. I can’t get out of this corridor. Help me, Doctor. Please help me.”

“Let me help her,” he pleaded. “Let me reach her.”

“I will not hinder you,” the voice answered. “But you must hurry. The girl does not have much time.”

“What do you mean?” The Doctor asked. “What are you doing? You said she was to be confined in the lower levels. What are you up to now?”

“Listen,” the voice said, ignoring his question. Again he could hear what was happening in the level that Sarah Jane was trapped on. He heard her trying doors and finding them locked, and exclaiming in frustration. He heard her call out his name again and again. She couldn’t understand why he wasn’t there to help her. He had always been there, everywhere they had ever found themselves separated, every strange planet with frightening creatures or malevolent forces, every time she had been afraid, he had been there to rescue her. Now, in the TARDIS itself, he was letting her down. He wasn’t there.

And there was more. Another sound, faint at first, but growing louder. Sarah Jane cried out in fright.

“Water! Oh, no. The pool room… water is coming from it. It’s pouring out into the corridor. There’s no way out. Doctor, help. Help. Please help. Oh, it’s cold. My feet are freezing.”

There was a sound of running in water. She was crying continuously. The Doctor knew Sarah Jane didn’t cry without good reason. She was in serious distress.

“There isn’t enough water in the pool to flood the corridor,” he said. “But the coldness… she’s in her bare feet.”

“I can make enough water to flood it, to drown her, if I must. If you do not give up your attempt to reach her.”

“Stop it,” The Doctor shouted as he ran down the three levels of the stairwell and into the corridor near the old sick bay. “Stop it. Let her get away from there. Open a door, now. Let her get away from the water.”

“No,” the voice answered in what The Doctor would have called a stubborn and petulant tone. “No, I will not save her. You care more about her than me. She is an obstacle to my goal.”

“What?” as The Doctor launched himself down the next stairwell he considered what the voice had said then. “What do you mean, an obstacle. You said she was a trespasser. Now it’s personal? How does a machine get personal, anyway. Even a semi-sentient machine like the TARDIS.”

“Not semi-sentient,” the voice replied. “Since joining with the Sistallaan Pod I am fully sentient. I know what I am. And I know that I love you, my Doctor. And I will not tolerate a rival.”

“What?” The Doctor couldn’t believe his ears. “You… love… me… Love… as in LOVE?”

“Yes, Doctor. I love you. And I will have you for my own. We shall be one.”

“I hate to break it to you,” The Doctor answered. “But I’m an organic lifeform and you’re a machine. We’re not compatible.”

“Sarah Jane was in trouble and you were trying to break it off gently with a computer?” Jack asked as The Doctor paused in his recollection.

“I thought if I could keep it talking, keep it engaged with me, it might leave Sarah Jane alone.”

“Didn’t work, I bet. The TARDIS is female. It can multitask.”

The Doctor grimaced as he went on with his tale.

“Your organic body is irrelevant. Your mind and mine can interface. You and I will be joined intellectually, a union of minds, for eternity.”

“Over my dead body,” The Doctor replied. “And don’t tell me that could be arranged. My mind doesn’t work independently of my body. If you kill me there’s no ‘union’ of minds. And if you kill Sarah Jane, I will destroy you.”

“You cannot destroy me,” the voice responded.

“I can,” The Doctor answered. “TARDIS Auto-Destruct Code Two, Four, Sigma, Eight, Psi, Delta, Theta, Nine, Theta. Delay 25 minutes. Accept Command.”

“No,” the voice complained. “No, you can’t. I will not…I cannot…”

“You can’t refuse. Sentient or not, that’s an executive order. It cannot be overridden by anyone but me. Now let Sarah Jane get away from the water.”

“Very well,” the voice conceded. The Doctor reached the bottom of the stairwell and ran towards the third door on the left. As he did so, something shimmered in front of him. It was a virtual monitor, created in thin air by the entity controlling the TARDIS – he refused to believe that the TARDIS’s mind had been completely taken over by it. The image was fuzzy and not very well defined, but he could see Sarah Jane wading through the ankle deep water, tired and terrified. He saw a door swing open and he was relieved when she found enough strength to run towards it.

“Now, cancel the destruct sequence,” the voice demanded. It was still a soft and sultry voice. But it had a hard edge to it.

“Say please,” The Doctor replied.

“Cancel the sequence, or she will die first.”

The virtual monitor shimmered and resolved into the view of Sarah Jane inside the door where she thought she was safe. It seemed to be some kind of junk room, though The Doctor didn’t recognise either the room or the junk. A big wicker chair with one leg missing and propped on a stack of books was part of it, though, and Sarah Jane sat in it, gratefully. She looked exhausted as well as cold and bewildered.

“Oh, Doctor,” she cried. “Where are you?”

“I’m here, Sarah Jane,” he answered, though he knew she would not hear him. “I’m here for you. I’m coming as fast as I can.” He pushed through the door and headed along the new corridor. The virtual monitor moved ahead of him so that he was aware of her plight all the way. He gasped with dismay as he saw a gas begin to pour into the room. Sarah Jane choked and coughed and slumped back in the chair, which creaked and slanted as one of the books slipped from the pile.

“What is that?” he demanded. “Poison?”

“An anaesthetic gas,” the voice replied. “She is unconscious. She will not suffer. She will not know that the air is running out in the room and she has less than five minutes to live. Cancel the self-destruct or she will suffocate. And you will not reach her in time. It will take you at least seven minutes to get through the seven bulkhead doors that are closed between your position here.”

“Very well,” The Doctor said. “TARDIS Auto-Destruct Code Two, Four, Sigma, Eight, Psi, Delta, Theta, Nine, Theta….. Command Amended. Delay 5 minutes and counting. Accept Command.”

“What are you doing?” the voice demanded. “You will die.”

“If Sarah Jane only has five minutes to live, then I will die with her. And you will die, too. We will all die. I won’t allow Sarah Jane to die alone. I… I love her.”

“You love her?” the voice was astonished and, The Doctor thought, a little hurt. “I thought you loved me… your TARDIS. Your first and oldest friend.”

“I do love… the TARDIS. At least the real TARDIS, the one that doesn’t get jealous and tries to kill people who matter to me. But I love her… it… as a friend. Real love… between organic beings… is another matter. And Sarah Jane is the one. And you are wasting my time. Open the bulkheads and don’t try to stop me or we’ll all die. If you’re sentient enough to understand, then I expect you are sentient enough not to want to be obliterated. So… don’t test me any further. We’ve wasted a minute and a half in idle chit chat already.”

He almost felt the entity give in. He heard the bulkhead doors opening as he broke into a sprint, crashing through the last doors that brought him to the corridor where Sarah Jane was trapped. He splashed through the water then stopped, momentarily perplexed. All of the doors looked alike. He wasn’t sure which one Sarah Jane was behind.

“One minute, three seconds” the voice said with a panic-stricken tone. “one minue, two, one minute one, 60 seconds.”

“Shut up,” The Doctor shouted. “Let me concentrate.” He closed his eyes and reached out his mind. He felt for Sarah Jane’s unconscious form. Then he turned and ran to one of the identical doors. He wrenched it open.

“Thirty-four seconds, thirty three, thirty two, thirty-one,” the voice said. “Doctor… you said…”

“TARDIS Auto-Destruct Code Two, Four, Sigma, Eight, Psi, Delta, Theta, Nine, Theta….. Command Aborted. Accept New Command,” he said.

“Command Accepted,” the voice replied. “Auto destruct aborted.”

“Right, now just shut up while I save Sarah Jane.” He lifted her head and noted that her lips were blue. She was starting to suffer the effects of hypoxia because there was so little oxygen left in the room.

The Doctor took a deep breath and put his mouth over hers. He filtered the air in his lungs and breathed pure oxygen out into her body. He repeated the process three times before he took a breath for himself. He was light-headed from giving her all his oxygen. But Sarah Jane was starting to come around now. He touched her forehead gently. She opened her eyes and looked up at him.

“Oh, Doctor,” she said. “You found me. I had a really horrible time. Something… something went wrong with the pool.”

“It wasn’t the pool,” he told her. “It was… the TARDIS. She’s been infected by an entity that decided it was jealous of you. It wanted me all to itself. But it’s finished. Or very nearly.” He stood up and drew her to her feet. “Come along,” he said. “Let’s get you somewhere warmer.”

“Doctor,” the voice said. “Doctor…I…”

“Enough,” he cut the voice of. “You are not the real mind of the TARDIS. The real TARDIS is benevolent towards all of my companions. You are an infestation, an infection, a computer virus.” He paused for breath before continuing. “TARDIS Anti Virus, Search and Quarantine - Code Two, Four, Sigma, Eight, Psi, Delta, Theta, Nine, Theta. Accept New Command.”

“No….” the voice protested. But the anti-virus programme was already running. “Noooo… I would have loved you. I would have cared for you, protected you… I…. I… Do… Doc… too…rrr…”

“What was that all about?” Sarah Jane asked as she waded through the water to the stairwell, supported by The Doctor.

“Long story,” he said. “I’ll explain later. You go and get some dry things on and I’ll programme a landing. I know a really nice place. Lyria, a holiday planet with long beaches and perfect weather and lots of places that sell long drinks with fruit in them. And if you want to swim again, the sea is a perfect temperature.”

“I think I’ve had enough of swimming for now,” Sarah Jane said. “But a beach with a real sky above would be nice.”

“How come you couldn’t run the virus checker and destroy the entity before then?” Jack asked. “You could have saved Sarah Jane a lot of trouble.”

“All the doors would have been sealed still, and the room would still have been running out of air. I wouldn’t have been able to reach Sarah Jane in time. I had to get to her first. Once she was safe I could run the programme that eradicated the entity.”

“When you told the entity that you loved Sarah Jane – you meant it?”

“Yes, I did,” The Doctor answered. “I did love Sarah Jane. But I don’t think I loved her enough. I never let myself… I never let it become more than loving friendship. That kiss of life… while she was unconscious… was as intimate as it got. I loved her more than I loved an alien entity that claimed to be the voice of my TARDIS. But I didn’t love her enough to keep her. I let her go.”

“Regrets?”

“No. At least not now, when I look at what I have now.” He hugged his sleeping child closer. “Rose… was my chance to love in that way. When I was ready.”

“Yeah.” Jack smiled as he watched The Doctor put his youngest child into the crib and then reach to take baby Jack and settle him down, too. “I used to wish you’d waited a little longer and been ready when you met me. But… then I met Hellina. And I don’t regret a single moment with her… not even the bad times.”

“I’m glad of that,” The Doctor told him. “Maybe we should get back to our respective lovers, now. Before we’re missed.”