Marie looked around the wide plaza with interest. It was a place of two surprising contrasts. On one side was a building that looked like a combination of the old Wembley stadium, the Crystal Palace - the Victorian exhibition centre, not the football club - and Alexandra Palace. Across the plaza was a modern building with lots of glass and shiny chrome that had an early twenty-first century ‘green building’ look to it.

"Melbourne Museum," she read on huge banners fluttering outside the modern building that had obviously been designed to take on an expanded range of exhibits that the old site could not do justice to. She looked at the wide puddles across the flag-stoned plaza and up at a grey, leaden sky that promised more rain. "Melbourne, Australia?"

"No, Lord Melbourne, otherwise William Lamb, 2nd Viscount Melbourne, Whig Prime Minister from 1834 to 1841," The Doctor responded dryly. "Which Melbourne were you expecting?"

"I wasn't expecting anything. You said it was a surprise and I would like it. I didn't expect Australia, and if I had, I wouldn’t have expected a sky like a wet Sunday in Templeogue. I have been thoroughly misled by the Aussie soaps."

"Never mind. This place is fascinating. Come and have a look at some of your planet's history sympathetically displayed by a clever bunch of museum bods – clever for you pudding heads, at least."

He took her arm and led her into the museum, getting his bearings and then turning towards a section called the Dinosaur Walk. Marie stopped him just at the entrance to the exhibit.

“Not yet,” she said. “There’s a school group in there. I’ve had enough of that sort of thing. Let’s wait until things are a bit quieter and I can ENJOY the experience for myself, without having to listen to the sound of crisp packets rustling and kids asking daft questions and wanting the loo.”

The Doctor smiled grimly and teased Marie about her aversion to children despite her chosen profession.

“You feel the same way about school field trips,” she replied.

“Yes, I do,” he conceded. They both pretended to be very interested in a poster advertising upcoming events until the echo of children’s chatter and the voice of the teacher trying to be heard above them died away.

“They’ve gone into the ‘Education Room’,” The Doctor confirmed at last and they moved into the beautifully organised section of the museum dedicated to the prehistoric animal life of Australia. Carefully re-constructed skeletons of flying pterosaurs like Quetzalcoatlus and Pteranodon were suspended from the ceiling, with a close up view from the mezzanine floor, while at ground level the long necked and placid herbivore Mamenchisaurus and his fellow vegetarian, horn-faced Protoceratops, were stalked by the turkey shaped carnivore, Gallimimus and the smaller but nastier, Deinonychus, meaning ‘terrible claw’.

Marie had the basic knowledge of dinosaurs that the average follower of the Jurassic Park series might manage, so most of those names were new to her. She noted that herbivores far outnumbered and outgrew the carnivores in the wide open plains of prehistoric Australia. She also discovered that not all of the exhibits were, technically, dinosaurs, despite the name of the exhibition.

“Wow…. It says here that Megalania prisca could have been hunted by early aborigine tribes. I thought dinosaurs were wiped out long before Humans existed. The comet strike….”

“They were,” The Doctor answered with a strange catch in his voice as if he were personally involved in the catastrophe. “Megafauna are not dinosaurs. While still huge – this fellow was quite capable of eating a shrimpy pudding head like you – they are much smaller than the ‘terrible lizards’. They roamed your planet much later than their giant chums. In fact, the term Megafauna is still used in your time for creatures such as the elephant, rhinoceros, and in your oceans, the whales. Historically, they include the likes of the woolly mammoth and this chap here - Diprotodon optatum - who was the granddaddy of much more cuddly species like the wombat and koala. Megalania himself is an ancestor of the Komodo Dragon, the largest extant lizard on Earth.”

“Yeah, I know about those,” Marie conceded. “I mean, I’ve not been up close and personal with them, but… you know… David Attenborough has, and I’ve seen his programmes.”

“He hasn’t seen a Megalania,” The Doctor said with a grin that was reminiscent of some of the fearsome skeleton heads in the exhibition. “There have always been rumours of a few still existing in the Australian wildernesses.”

“That’s got to be an urban myth,” Marie insisted. “Or whatever you call an urban myth in the middle of nowhere, at least.”

"Some of those urban myths are not so far from the truth," The Doctor replied. "The Great Bear of Berlin... the giant rat that haunts the river Fleet.... I can vouch for that one. I met it in a little scrap with Victorian triads and a murderous fiend from the far future."

"Yes, but what about Megalania here?"

“No, I'm afraid that one is very unlikely. You won't see Megalania hunting down Diprotodon without travelling back in time to the Pleistocene era."

Just as he said that, somebody screamed in the entrance lobby, the sound eerily echoing around the Dinosaur Walk. Then lots of people screamed and by the time The Doctor reached the scene of the panic they were running in through the wide main doors as if the dinosaur-killing comet was heading their way.

The Doctor, as anyone who knew him could predict, ran the other way - towards the source of the consternation. Marie sighed and followed him outside as a fearesome roar split the air.

"Oh, my God!" she exclaimed as she stepped past the row of flagpoles outside the museum and stared at a huge lizard biting into the foreleg of something equally huge, furred and with protruding front teeth under a bulbous nose.

"Doctor.... is that...."

“Yes," he replied. "That is a Megalania devouring the leg of a still kicking and fighting Diprotodon, in broad daylight, in the plaza of Melbourne museum, in the year 2016."

"But you said...."

The Doctor’s expression was dark. Marie was fairly sure it wasn’t because he had just been proved wrong over a fairly certain declarative sentence - though she wouldn’t have blamed him for that, all things considered.

“No, no, no, no, no, no, NO!” he exclaimed. “This does not happen.”

“It’s happening,” Marie managed to say. Behind her, the school children were pouring out for a look, despite the exhortations of their teachers to get inside. They were giving their own running commentary about how much blood there was, about how the Diprotodon had ‘had it now’ as its whole leg was ripped off and the Megalania went for the soft underbelly. When its internal organs slid out into the pool of gore she had to look away, but the children carried on watching in fascination.

The Doctor, of course, did more than look. He ran towards the Megalania, his sonic screwdriver held out in front of him, taking readings of… whatever. He circled the carnivore and its unfortunate meal, murmuring under his breath, clearly engrossed in his experiments.

“It’s true!” exclaimed a voice behind her. It belonged to a dark-skinned man called Brian Beangagarrie who was, according to his identity tag, Curator of Megafauna. “It’s really true. I can hardly believe what I’m seeing. What is that lunatic doing?”

“I’ve no idea,” Marie answered. “But I’m sure he does. Best to let him get on with it.”

“How did it happen?” Beangagarrie asked.

“Still no idea,” Marie told him.

“It just appeared, like magic,” said one of the school kids. “We were looking out of the window, because the film we were watching was dead boring, and it was just there… eating the other one. We heard it roaring in pain as its leg was ripped off.”

That was the absolute consensus among the chief witnesses, all of whom were eleven or twelve years of age and not even remotely scared of what they were looking at, or traumatised by the blood and gore spreading across the flagstones as the Megalania, its long face covered in blood and tail whipping back and forward, continued to feed.

It was taking no notice whatsoever of The Doctor. Marie wondered if it could actually see him. Perhaps this was some sort of time warp in which the Megalania and the now deceased Diprotodon were still in a kind of bubble of their prehistoric world, but somehow projected into this time.

She knew she had been with The Doctor for long enough when theories like that were forming in her head. She congratulated herself on not screaming, crying or throwing up, which several women and one or two men safe inside the glass doors and windows of the museum were doing and wondered if there was any other theory that explained all of this.

“I don’t think it’s real,” said a girl with a plastic rainhood tied under her chin but pushed back from her forehead to reveal ash-blonde hair. “I reckon it’s one of those animatronics, or maybe a really good hologram programme – for publicity.”

“It most certainly is NOT,” Beangagarrie replied quickly. “They would NEVER give us the budget for something like that. Whatever it is, the museum has nothing to do with it. I only wish we did. It would make sense. The only other explanations don’t.”

“And what are they?” Marie asked him.

“Well… some kind of time travel thing,” he conceded. “Something pulling creatures through time. That or… well, I’m sure they aren’t the mythical survivors living in the Outback. We’re in the middle of Melbourne, and according to these kids, they just appeared out of thin air.”

“Well thought out,” Marie told him, feeling sure that The Doctor would agree. She had ruled out the urban myth herself. Something to do with time distortion was the only plausible explanation.

Which, again, only showed how far her grasp of what was plausible had changed since meeting The Doctor.

“Something weird is happening," the blonde girl said. Marie gasped in astonishment along with everyone else as Megalania, the remains of the eviscerated Diprotodon and The Doctor were enveloped in a shimmering haze and began to fade away. A translucent Doctor spun around and looked directly at Marie, mouthing a warning to stay back.

Then he vanished, along with the creatures. All that remained was a pool of thick blood on the flagstones.

"Doctor!" Marie screamed. "No... where is he?"

She ran towards the place where he had been. The smell of blood and half-eaten Diprotodon guts was sickening and the only sign that anyone had been there were some bloody footprints around the outer edge of the area.

"You knew there was some sort of zone!" she murmured. "But you stepped inside, anyway. You daft alien."

She started to cry, not only because she realised she was alone in Australia, but also because The Doctor might be in terrible danger. If he had been taken back in tine along with the Megalania then he was trapped in a hostile world with no way back.

It was Brian Beangagarrie who came to her aid. As the teachers finally got their school party back into the education room he brought her into the staff area beyond a key-coded door. There, in a cool, airy, open plan room that was part office, part science laboratory and part common room she was given tea and kindness. She sat now in a chair, hugging the half empty mug and looking at the plaza on a closed circuit TV. The police had arrived, but all they could do was put incident tape around the area where the unlikely incident had occurred. It was raining again now and the blood was washing away into the cracks between the flags. One of Brian’s assistants had gone out before the downpour and fetched a sample. He was busy examining it under a microscope.

"There are traces of bacterial venom in the Diprotodon blood," he said to Marie, just to give her something other than The Doctor's disappearance to think about. "It was always believed that Megalania poisoned its prey to render it helpless. This would be the absolute proof of that theory. .. if anyone would believe me."

"Those kids all had their mobiles handy. I'm sure they've uploaded to You-Tube and Instagram by now. People will have to believe. I really hope you have something out of it. I mean it. Even if... if The Doctor is gone for good... and that's terrible for me and for the whole world … the whole galaxy... I do hope you learn something about your Megafauna."

"I think we will learn a lot. but... maybe there are more important things. The Doctor... he's not just a lunatic that runs around waving a torch at ravenous reptiles?"

"It’s a sonic screwdriver, and no… he's...." Using the present tense helped her to keep believing that he was alive and he would be coming back. "He's the smartest man this planet has ever known. He's...."

"A time travelling alien?" Brian suggested.

"How do you... I mean.... what makes you think...."

"I heard the two of you talking in the dinosaur exhibition. He talked about Earth as 'your planet' and he mentioned something about Victorian triads. And the way he ran towards the Megalania... while everyone else ran away. It was as if this sort of thing was normal to him."

"Not quite," Marie admitted. "He was as surprised as any of us by the creatures."

"But the rest…. Don't worry. On a day like today I'm ready to believe anything."

"He is a time travelling alien."

"And you?"

"I'm a teacher from Dublin. l do this on my day off."

“Interesting hobby.”

“Yes, it is. But… If he doesn’t come back… we came here in his time machine. I didn’t bring a passport. I’m an illegal immigrant to Australia. It’s just as well he brought me to my own time, but I’m still in a lot of trouble.”

“Don’t give up hope. If something can pull Megalania out of the Pleistocene era, maybe it can bring your Doctor back. Let’s just assume he’s MIA for now.”

“I’m trying,” she admitted. Then her attention was drawn back to the CCTV. There was another patch of shimmering light and something was materialising within it. For a moment she hoped it might be The Doctor, but the man who solidified was an aborigine with a spear raised ready to strike at what Brian, a man used to talking in Latin species names, identified as Thylacoleo carnifex.

“Marsupial lion to you,” he added as he dashed towards the emergency exit that emerged onto the plaza. Marie followed. The Thylacoleo was dead, now, the spear through its heart, but the man, his body so covered in tattoos that he was nearly ochre coloured, was staring about himself in fear.

Brian tried to speak to him in an aboriginal dialect, but even in the twenty-first century there were many of those, and the one he knew wasn’t making any sense to the late Pleistocene hunter.

“I might have a surname passed down through countless generations, but I was born and raised in Melbourne. My first language is English,” Brian explained helplessly.

“He says that there are ghosts everywhere,” Marie told him. The TARDIS translation circuits were still working upon her and she understood perfectly. “I think he means white people. He’s never seen a Celt before!”

She spoke gently to him, pointing to Brian and insisting that he was a friend. The two men had common ancestry, but one was in a smart suit and tie, the other in a loincloth that smelt distressing even from a distance. The common ancestry seemed to help, though. Brian managed to understand a few root words of early Pintupi that convinced the hunter that they were the same species and that white skinned people were not ghosts.

But trust was still not quite established. Around them tourists were snapping photographs and exclaiming loudly. The camera phones were bad enough, but some of the bigger models had bright flashes that reflected off the puddles. The hunter thought he was in the middle of a lightning storm.

“Let me help,” said a familiar voice that came from a figure Marie barely recognised at first sight. The Doctor, his clothes in rags and his face as heavily painted in mysterious symbols as the aborigine hunter, dashed past them. His startling features seemed to reassure the native much more than Marie or Brian’s efforts and he let him touch his shoulder. The Doctor spoke in a low tone that gradually took on the hypnotic hum of a native musical instrument and the bewildered hunter suddenly collapsed in his arms, lulled into a peaceful sleep. Brian pulled the spear out of the body of the dead Thylacoleo and told Marie to lead the way back to the privacy of the staff room.

The hunter was still sleeping quietly on two armchairs pushed together as The Doctor, still looking fearsomely native, was drinking tea and doing things with Brian’s computer that it was never meant to do.

“There, every picture of living Megafauna uploaded to the internet has suddenly been corrupted. Let that programme run for a few days to catch the rest, and the whole thing will eventually be forgotten by the pudding heads with the attention span of goldfish that inhabit this planet.”

Brian was disappointed to know that all evidence of the most dramatic time in his career in palaeontology was obliterated. Marie demanded to know where The Doctor had been for the past hour.

“For the past hour… trying to avoid drawing attention to myself while getting back to here from a place called Point Cook Coastal Park, where I emerged through a time window along with a specimen of Procoptodon - Giant Short-Faced Kangaroo to you - which is still running around scaring picnickers. For the past three WEEKS I have been in the Pleistocene equivalent of Point Cook, where I narrowly avoided being married to the chief’s three daughters all at once – which is three wives more than I want or need.”

“So you were all right,” Marie said with relief. “You weren’t eaten by a Megalania…. Well, obviously not….”

“I was nearly MARRIED,” The Doctor repeated. “A fate WORSE than being eaten by a big, venomous lizard. I did EAT Megalania steaks on several occasions. Roasted over an open fire it’s a lot like barbecued chicken.”

“You were gone for three weeks?” Marie queried, trying to bring him back to the salient point.

“Time windows are strange that way. Remind me to tell you about me and Madame Pompadour, sometime. Hey… you… Brian… is that a phial of Diprotodon blood you have there? I hope you’re not thinking of doing anything stupid like trying to clone a long extinct carnivore.”

“Not bloody likely,” Brian replied. “I SAW Jurassic Park when I was a kid. I just want to keep something to remind me that I wasn’t dreaming all this now that it’s over.”

“It’s not over,” The Doctor told him. “I still haven’t found out who is creating the time windows and bringing these creatures out of their proper time zone. It’s not a natural rift like that motley crew in Cardiff keep an eye on. Somebody has been making this happen… somebody with more than a rudimentary grasp of time travel. Pleistocene Melbourne is littered with time traps set to go off when animals step into them. The traps are calibrated to pitch up around this building. I artificially triggered one of them - that’s why I arrived a few miles away – but the rest of them should appear in and around the plaza any time now.”

"You mean there could be more animals turning up?" Brian stood abruptly and reached for the fire alarm that would warn staff to evacuate the building.

"Not a good idea," The Doctor warned. "You'll be sending them out to assemble on the plaza.... gourmet dining for the megafauna."

"But there are still a hundred or more people in the building," he said. "We have to do something to protect them."

“Do you have some kind of procedure for a bomb alert – something that gets people right away from the whole complex?” Marie suggested.

“Yes, yes, we do,” Brian remembered. He reached for a telephone with the emergency code already programmed into it, but an ear splitting roar and multiple screams told them that it was already too late. Marie opened the door into the dinosaur walk and confirmed that another Megalania had appeared among the skeletal exhibits and was knocking them to pieces as it ran after the fleeing visitors and staff. As she watched it lumber past, a second Megalania materialised as well as a Diprotodon and two snarling Thylacoleo that were backing it into a corner and preparing to go for its throat. Marie shut the door again. She went to the emergency exit and confirmed that the plaza was filling up with panic stricken people who found themselves surrounded by even more Pleistocene era Megafauna.

“People are going to die," she said. "If they don’t get trampled by herbivores they’ll be ripped to pieces by Megalania and his pals."

"We've got to stop this," Brian acknowledged. "Doctor, you seem to have some idea of what's going on. Now is the time to share."

"My idea is that somebody in this museum is controlling the time windows. That’s why the creatures are arriving here. I presume time travel experiments aren't something your Board of Trustees has sanctioned, so it has to be somebody working in secret. Do you have any labs that are off limits even to senior staff like yourself?"

"No... at least... not off limits as such, but the director... Nigel Hamilton.... He's working on a project involving rock samples from the Jenolan Caves – in the Blue Mountains - the oldest known cave system in Australia. He keeps them in a basement room. He says it is important to study them in an underground environment. But it’s not exactly off limits… just not on the beaten track. I mean, I've never had any reason to go down there. Come to think of it, I don’t know anyone who has."

"And that sounds plausible to you?" The Doctor asked. "Rock samples."

"Sounds unlikely to me," Marie said.

Brian shrugged.

"Look, don’t blame me. I'm a palaeontologist. I don’t study rocks. I hack at them with hammers and chisels to get to the fossils inside."

"Show me the way to this subterranean laboratory," The Doctor ordered. He went to the sleeping native and put his hand across his forehead momentarily. "Our chum here will sleep a bit longer. He'll be perfectly safe."

"We might not be. The stairs to the basement are on the other side of the dinosaur walk."

"Stay behind me, then," The Doctor said, wielding his sonic screwdriver manfully.

"It tends to be the safest place when things are running out of control," Marie confirmed.

The dinosaur walk was looking more like a dinosaur massacre. There was barely a skeleton left intact. Several of the Thylacoleo had worked out how to get up the escalator to the mezzanine level and had clawed the wires holding up the Pteranodon. Looking up now into the faces of those lion faced carnivores as they peered back down over the glass parapet was distinctly unnerving.

"We have to get past those," Brian whispered, pointing to the three Megalania currently tearing up both the fossil remains and an actual, flesh and blood great kangaroo that they had brought down with their vice-like jaws and venomous bite. Beyond them was the door with the staff only sign and a key-coded lock.

The Doctor went first, holding up the sonic which emitted a strange, low sound.

"I'm reproducing the pheromones of a bigger, angrier male Megalania," he said as the three reptiles looked up from their meal and then moved away quickly. "It is something I learnt to do in my Pleistocene interlude – while avoiding the attentions of the chief's daughters."

"It's working," Marie commented. They reached the door and Brian keyed in the pass-code.

"Damn, he's changed the code," he swore.

"Let me," The Doctor told him. "The sonic does electronic locks. You keep the fauna back."

"How?" Brian asked, nervously looking up at a snarling Thylacoleo that was ready to leap down from the mezzanine.

"I wish I’d kept hold of that spear," Marie commented, though she wasn't sure, even in desperation if she could use it against a living creature - especially not one that had been hunted to extinction once already with such weapons. It was just wrong.

On the other hand she didn't want to help the species survive a second time around by being its lunch.

The Thylacoleo growled. She looked it in the eye and growled back, curling her hands into a claw-like pose. She hissed and snarled like a really bad tempered alley cat.

To her amazement it worked. The Thylacoleo backed off.

“Well done,” The Doctor congratulated her. “You’ve found the pheromone that matches a female marsupial lion defending her den.”

The lock clicked, its low sound strangely audible against the din around them. The Doctor pushed open the door and waved Marie and Brian inside before closing it behind himself and applying a deadlock that might just hold back the Megafauna for a little while.

A flight of stairs, dimly lit, in a section of the building that nobody had thought to bother decorating even with a coat of plaster over the brickwork, led down to the sub-basement. An equally dimly lit corridor stretched into the distance.

“There are storage areas here,” Brian explained. “Archives containing thousands of artefacts that are never likely to be on display upstairs as they’re only of interest to scientists. There’s also a tunnel that goes right under the plaza to the old building, for transferring exhibits. Doctor Hamilton’s lab is right down this way.”

There was another key-controlled lock on the door. The Doctor made short work of it before stepping inside without bothering to ask permission. Marie and Brian followed him in.

“Ah, now I’m starting to understand!” The Doctor said as he looked at the two occupants of the room. “You must be Doctor Nigel Hamilton. I’ve heard very little about you. And your companion… I don’t know your name, but I have heard a great deal about your species. Somebody in England a long time ago called you Silurians, but as both Doctor Hamilton and my friend Brian here will certainly confirm that was a complete misnomer. You properly should have been called Eocenes. I’ve also heard the term Psionosauropodomorpha, but that’s too much of a mouthful for any of us to swallow. Homo Reptilia was suggested, but that’s not right, either. Let’s plump for Silurian for the sake of consistency. But my point is, given your hatred for Homo Sapiens, I can’t help wondering why you’re working with one of them.”

“I am Geccic,” hissed the Silurian/Eocene/Psionosauropodomorpha/Homo Reptilia, henceforth known as the Silurian. “I represent the Antipodean tribes of the noble and superior race that rightfully belong upon the surface of this ape-infested planet.”

“Doctor Hamilton?” Brian passed over the fact that a reptilian man with two yellow eyes and one dull red one in the centre of a bony forehead had turned from the array of computer screens he was monitoring and was glaring at him in hatred. He concentrated on the startled expression on his superior’s face. “What’s going on? Are you involved with the carnage upstairs?”

“I certainly don’t see any rocks being studied in here,” Marie pointed out. The room looked more like ground control at NASA. Huge servers were blinking away all along one wall and the hum of the power units was almost overwhelming.

“Oh, that was an obvious lie,” The Doctor told her. “I’m guessing that Doctor Hamilton met up with his friend, here, while exploring the caves. Between them they’ve set up some quite remarkable technology. Geccic, I always knew that your people were technologically advanced, but I didn’t know they had developed time travel. You’re using it, of course, to bring the extinct Megafauna to the present day, no doubt with a view to wiping out modern humans and their society, before restoring your own people to their – as you say - rightful place as the dominant sentient species.”

“What?” Hamilton queried, turning to Geccic questioningly. “You said we were collecting specimens to enhance the museum profile. Instead of skeletons, half of them finished with carbon fibre because they’re incomplete, we were going to have whole bodies on display, the skin, fur, scales….”

Geccic made a disgusted sound in his throat at the mention of scales.

While all of this helpful exposition had been going on, The Doctor had moved around to the computer system and was now examining it carefully. Hamilton and Geccic were too busy arguing between each other to notice.

“You didn’t have enough power, did you?” he said casually. “You probably wanted the Jurassic era with the really big lizards, but the Pleistocene was the best you could do, and you haven’t been able to stabilise it, yet. Everything keeps snapping back to its proper place.”

“What are you doing?” Geccic demanded. “Get away from there.” He raised his arm and pointed a clumsy looking but very effective thermic weapon at The Doctor. He knew that he was seconds away from excruciating death.

“I wouldn’t do that,” Brian called out. “Not if that computer behind him is important to you. Your death ray will fry a few circuits, at least.”

Geccic hesitated momentarily, because Brian was perfectly correct. The thermic weapon would do untold damage to the time travel controls. Instead the Silurian moved far more quickly than anyone, even The Doctor, expected, and grabbed Marie around the neck.

“No!” Hamilton exclaimed, lunging towards Geccic.

“Don’t do that!” Brian lunged at Hamilton, bringing him to the floor at the feet of the Siliurian.

“I can snap her in half, as you know very well, if you know my species,” Geccic warned. “I can also poison her with one scratch that breaks the puny Human skin. Move very slowly over there where I can kill you without damaging anything other than your miserable ape body.”

“I’m not descended from the apes,” The Doctor replied, though he was doing as he was told very slowly. “My people’s primitive ancestor was called….”

He never finished his sentence. He didn’t need to. What nobody had noticed was that he had been adjusting dials on the control all the time he was talking. The air around Geccic, Marie, Brian and Doctor Hamilton was shimmering. That wasn’t exactly the plan. The Doctor had fully intended to affect just the Silurian and his Human collaborator. This was a complication that he would have to deal with later.

Marie fell out of the startled Silurian’s grasp, landing on top of the tangled arms and legs of Hamilton and Brian. She rolled over onto a damp patch of leafmould and looked up into the tree canopy above. As she began to realise that all four of them had been sent back in time through one of those time windows, there was a terrible roar. Geccic began to scream before the sound was cut off – along with his head. Marie watching the rest of his body fall like a tree towards the Megalania that had attacked him. She wanted to stand up and run, but her legs felt like jelly. She was sure she was going to be part of the Pleistocene food chain any moment.

She wasn’t. Nigel Hamilton was. Brian was distracted enough to let him free, but he blundered straight into the path of the Megalania and was cut down mid-stride.

“Keep still,” said a familiar voice. From her viewpoint she could only see a pair of legs step across her and the pale blue tip of the sonic screwdriver emitting the pheromones of a larger, angrier Megalania.

The creature backed away leaving the two bodies of a Silurian and a Human behind. The Doctor reached to lift Marie to her feet and then did the same for Brian. It was then that they both noticed the TARDIS parked at the edge of the clearing and the native hunter, complete with his spear, standing by the open door.

"Can you find your own way back hone from here, Barega?" The Doctor asked. “You two met Barega, of course, but I don’t think you got around to formal introductions.”

"Yes," Barega answered. "May you journey well, Doctor."

With that, he turned and melted into the wild Pleistocene woodland.

"Good chap, Barega," The Doctor said. "He's been helping me out. Come on, both of you, one dropped off, two picked up. Off back to Melbourne."

"How long has Barega been helping you out?" Marie asked as The Doctor set the co-ordinates and the TARDIS left the Pleistocene era. "I ask because you seem to have managed to have a shower and a shave and a change of clothes, while we were there just long enough for the bad guys to lose their heads."

"A week," he answered. "It took that long to shut down all of the time traps, send all the Megafauna back where they belong and fix the temporal-spatial location where I sent you all. By the way, Brian, a little known special forces group called UNIT came in to sort out the mess at the museum. They debriefed all the witnesses and convinced them all that they were suffering from hallucinations caused by a pocket of Sallonic gas in the underground car park. There are, I am sorry to say, four fatalities, one member of staff and three visitors. Their relatives have been informed. Compensation has been arranged. In his absence, the Director has been dismissed for failing to maintain health and safety. You have been on sick leave. Is that all right?"

"It's... fine... except ... what's Sallonic gas?"

"It’s what happens when a Sallo bear from Arturo Vector eats too much fresh fruit, but nobody else will worry about that."

“And this is your idea of a day off from teaching?” Brian said to Marie.

“It beats spending the day in front of the telly,” she answered.