Amy was making the fresh pot of coffee when she heard a key in the front door. She went to meet her husband and warn him about their visitor. His reaction was a mixture of excitement and wariness just as it had always been when River turned up. It was always exciting when she was around, but also just a little dangerous.

“It’s ok,” Amy assured him. “She just came to catch up on old news. We’re having coffee and sandwiches in the drawing room.”

When Amy brought the refreshments, Rory and River were talking about Brian, Rory’s dad. River had been to see him several times. He was getting on all right, missing them both, but pleased to know they were alive and well in their new life. He had told the neighbours that they had emigrated to Australia. Everyone fully believed that.

“Give him our love when you see him again,” Amy said.

“I will. But I think it’s time I heard the rest of this story – the Calf Island Incident.”

“You came to ask about that?” Rory queried. “How did you even know about it? That file is classified. It can’t be opened for a thousand….”

“Yes. We’ve had that conversation already,” Amy told him. “We’d got as far as pulling Turner and Drechsler out of the lake.”

“Yes,” Rory said, his own mind casting back to that spring evening when an otherwise pleasant day had taken a nasty twist.

Spirits were revived by a camp fire and hot cocoa in the dying light of the day. The analgesic cream eased the stings everyone had suffered. Even Turner and Drechsler were looking better as they sat and joined in a selection of rousing camp fire songs in both English and German.

“I should examine that water tomorrow,” Rory said later when they had all retired to their tents and the camp fire was a red glow in the starlit night. “If there is something dangerous in it, there are authorities that would need to be informed.”

“I’ve never heard of anything dangerous in fresh water. Especially fresh water in a lake on an island in a lake of fresh water. Nothing could be safer, surely?”

“On Earth, I would have thought so. Remember that place The Doctor took us too, once, with the huge acid lakes. Imagine swimming in that.”

Amy remembered.

“There are a lot of weird things in the universe.”

“There’s a lot of beauty in the universe, too. Even those lakes were amazing. Remember the fantastic shapes on the beach – crystals accreted by the acid tides built up into fans and stems like petrified plants.”

“And a lot of ugliness on our planet,” Amy added. “The war… the things the Nazis have done all across Europe. The Bomb that the Americans are going to use in a few months time.”

“Yes.” Rory sighed. “We can’t do anything about that, of course. It would be exactly the sort of thing The Doctor would tell us not to interfere in.”

“I know. As if there is anything we could do anyway. We’re not very important in the scale of things. ”

“That’s one of the good things about living in this time and place. We’re nobody. We can keep our heads down and avoid trouble.”

“Yes,” Amy agreed. That was the reassuring thought that they settled down to sleep with in their tent.

It was still dark when they were woke suddenly by a gunshot and a scream. Rory leapt from his camp bed.

“No!” Amy called to him. “You don’t even have a gun. It’s not safe.”

“I’ve got to find out what happened,” he answered. “I’m in charge of the prisoners. I’ll be careful. I promise.”

He didn’t carry a gun, but as he crossed the campsite he picked up one of the baseball bats that had been used in the game yesterday afternoon. He carried it defensively as he approached the tent where a noisy disturbance continued.

“What’s going on?” he asked as he pushed his way in and saw Warner and Nolan trying to restrain Sergeant Turner. They had taken his side arm from him but he was fighting them off desperately. Only with Rory’s help did they manage to force Turner down onto his bed and secure his hands behind his back so that he couldn’t hurt himself or anyone else.

“What started this?” Rory asked while he examined Turner and found his eyes dilated as if he was in a trance. He was sweating profusely and though he had stopped shouting, he was still murmuring incoherently.

“He was talking in his sleep,” Warner said. “But then he started shouting, and he fired a shot – it ripped the tent.”

Rory noted the hole in the canvas. It was small and neat. Where the bullet eventually ended up he couldn’t say without a CSI team to work it out.

“What was he shouting about?” he asked.

“He thought he was being attacked,” Nolan answered. “By one of the prisoners.”

Rory was startled by that idea. He looked around as if expecting a knife wielding German soldier about to attack them all.

“There was nobody here, and the prisoners’ tent is quiet,” Warner pointed out.

At that exact moment, a scream rang out from the prisoners’ tent. Rory turned and ran. Warner ran after him. Rory stopped and looked around at him.

“Leave your gun,” he told him. “I don’t think anyone is trying to escape, and we’ve already had one gun go off tonight.”

“Sir, I can’t do that,” Warner answered. “Apart from anything else, you’re unarmed. I have to protect you.”

“Oh, for goodness sake,” Rory protested. But there were other shouts coming from the big tent where the prisoners should have been sleeping. He didn’t have time to worry about it.

The tent was a big one. It had taken ten of the men to erect it. The camp beds were arranged in rows much like their beds in the barracks – neat and tidy and regimented, proving Rory’s point about how much they had become used to being prisoners.

Or at least they WERE neat and tidy. The tent was in disarray now. A lot of the men were out of their beds. Those that weren’t were sitting up, looking in horror at the struggle between Drechsler and two of the other prisoners who were trying to restrain him.

The scene looked strangely familiar to Rory. He waited until the prisoners had subdued their comrade, then examined him carefully.

He was the same as Turner, his eyes open but unseeing, sweating profusely and shivering at the same time, murmuring incoherently, in German, but otherwise just the same as his American counterpart.

“Warner, run to my tent and bring my medical kit,” he said.

“I can’t leave you here on your own, sir,” Warner answered.

“I’m fine,” Rory insisted. “Go. And leave that gun behind before you come back. There’s no need for it.”

Warner obeyed him after Rory insisted one more time. He turned back to Dreichsler who was starting to become a little more coherent in his speech, though still unconscious.

“Is he saying what I think he’s saying?” he asked the men who stood nearby. “Is he saying that one of the guards was strangling him?”

“Yes, sir,” answered a young man from Berlin called Fritz Kappel. “But… it isn’t true. There was nobody near him when he started shouting.”

The other prisoners backed him up. Rory examined Dreichsler’s neck carefully. There was still a redness to it from whatever had stung him in the water, but no bruising or other obvious signs of strangulation.

“He was hallucinating,” Rory concluded. “When Warner gets back, I’ll give him a sedative. He should sleep until morning. The rest of you get back to bed and try not to worry about him.”

“He is not a man who has nightmares,” Kappel said. “He is vernünftig, verständig….”

“Yes, I am sure he is as rational and sane as the next man,” Rory agreed. “But something disturbed him. I don’t know what, but it is over now. I….”

Two shots rang outside. Rory swore a swearword he learnt one strange afternoon on a space station in another galaxy and ran out of the tent.

He was surprised to see his wife pointing Warner’s handgun at the sergeant. He was yelling incoherently. Among his other reactions, Rory wondered if there was any word other than incoherent to describe the words he was screaming. They were definitely English – American English, anyway - but he could only understand one word in ten.

“What the &#*$£$ is happening?” he demanded as he manhandled Warner to the floor and held him down, noting that he had the same symptoms as Turner and Dreichsler.

“He came into the tent,” Amy answered. “He was shouting about somebody trying to kill him. He… thought I was attacking me and tried….”

“Tried what?” Warner was a well muscled man, and in a straight fight Rory shouldn’t have stood a chance, but he had him at a disadvantage and he was quite close to hurting him as his imagination ran riot.

“Nothing, not really,” Amy assured her husband. “I mean… he didn’t get a chance. I pushed him away. He dropped his gun. I fired into the air to make him back off.”

“Empty that gun,” Rory told her. “Go to the officer’s tent and tell them to empty their weapons, too. There’s something going on around here. So far nobody is really hurt, but if we have people with guns going nuts, somebody will be.”

Amy went to do as he said. Rory grabbed Warner up and brought him into his tent. He made him lie down on the bed Amy has just got out of. He was calmer now, but he was still shivering and sweating. Rory found his medical kit and prepared a sedative. He administered it to Warner. A few minutes later the Sergeant began to calm down. A minute later his eyes opened wide and he sat up, staring around in surprise.

“How did I get here?” he asked.

“Seriously, you don’t remember?” Rory asked. “You don’t remember attacking my wife, you don’t remember her shooting at you?”

Warner checked for his sidearm and found it missing. He stared at Rory.

“I attacked Mrs Williams? Is she….”

“No, she’s fine. But… what the heck….”

“I don’t remember anything except… I felt my arm burning… and then my head….”

Rory grasped his arm and shone his torch on it. Then he reached into his medical kit and found a pair of tweezers. He picked at something he had noticed on Warner’s skin. At first he couldn’t grasp it, but finally he pulled slowly and drew something like a long, thin thorn or spine out from under his flesh.

“What the hell is that?” Warner asked.

“I don’t exactly know,” Rory answered. “But I think I can guess where it came from. How do you feel now?”

“I feel… ok. A little confused, but ok.”

“Let’s go and look at your friend, Turner, next, then Dreichsler.”

“Ok,” Warner said. He had no idea what Doctor Williams was doing, but he followed him anyway. He seemed to be the only one who knew what was going on around here.

“How is he?” Rory asked Nolan as he entered the tent. Amy was still waiting there with the unloaded guns in her lap.

“Still rambling on,” the soldier answered. “Now he thinks there’s something trying to take over his body.”

“Stranger things have happened,” Rory told him. He again sedated his patient then used the torch to examine Turner’s body, especially around the chest where he thought he had been stung in the water yesterday evening. He saw one of the same spines under his flesh and carefully extracted it. This time he looked at it closely and thought it looked more like a very thin worm, except that it was rigid – dead, he hoped.

“He had a rash all over his chest last night,” Rory noted. “As if he had been stung dozens of times. But there’s only one of these under his skin.”

“Beats the hell out of me,” Nolan commented. “What is it?”

“I don’t know at the moment,” Rory answered. “But I think everyone who went swimming might have one. Turner and Dreichsler were in the water the longest. I don’t know how, but I think that has something to do with why they were affected first. But I think we need to get over to the prisoner’s tent.”

Even as he spoke, shouts and cries went up from there again. Nolan and Warner glanced at the guns. Rory picked one of them up and inserted a single bullet into the breach. He brought it with him as the three men rushed over to the other tent.

As Rory had fully expected, there was bedlam within. At least half the prisoners were screaming incomprehensibly while their friends tried to stop them from harming themselves or others. Rory knew he was never going to make himself heard above the noise, so he fired the one shot into the canvas roof of the tent.

“Everyone who didn’t go swimming yesterday, grab somebody who did and roll them back down onto their beds,” he said. Keep them as quiet and still as possible but don’t hurt them. I’m here to help.”

He went to Dreichsler first. He, like Turner, was badly stung on the chest, but there was only the one spine in his flesh. Rory pulled it out without using the sedative. He was running short and Dreichsler was calmer than before, despite the fever and delirium.

His conviction that it was some kind of worm or living creature was confirmed. It wriggled for a few seconds as he extracted it, before going rigid.

“Whatever these things are, they can’t survive in air,” he concluded. “And I think the sedative kills them off, too. Not so clever alien species.”

“Alien?” Those within his hearing looked sceptical or incredulous, all except Warner, who looked as if something finally made sense to him.

“Alien,” Rory answered. “Dreichsler will be all right, now. He should wake up, soon. Let me see the next patient.”

There was nothing else for it, but to attend to each of the stricken prisoners individually, examining them carefully for the place where the alien worm, spine or whatever it was had entered their body, and to extract it carefully with no more than a pair of tweezers and a torch held in a steady hand. Eleven of the prisoners were affected, all of those who went swimming. Removing the worms from under their skin relieved their suffering almost immediately, but he only had one pair of tweezers. He could only get to them one at a time. The delirious shouts and screams, the feverish cries, the sudden outbursts of violence continued for nearly an hour before he removed the last of the alien worms from the shoulder of the last prisoner.

It was almost dawn when he left the men trying to get some sleep after their trauma. He walked down to the lake where the drama had begun and looked at the water in the early morning light. It all looked calm and untroubled, in contrast to the people it had affected so very badly.

He looked into the lake carefully. With the sunshine shining on it yesterday afternoon it hadn’t really been possible to see down through the water, but now, with the sun still low over the bigger Lake Ontario, the pale blue sky above didn’t reflect so much of itself back.

Even so, the thing he was looking for was almost invisible on the lake bottom. It looked for all the world like a jellyfish, if jellyfish grew to the size of spitfires. Now he knew what he was looking for he could make out the nearly transparent form, the innards the same colour as the muddy lake bottom, the fronds loaded with those living spines reaching out just below the surface.

“Sir…” Sergeant Turner and his counterpart from the German army, Klaus Dreichsler, approached, along with Amy. Both the men looked disturbed but much better than they had been. “Sir, we have both…. I think, because we were exposed to the water far more… we both feel something about the… creature… that affected us.”

“Creature?” Rory questioned. “You know there is a creature in the lake?”

“I felt its mind,” Dreichsler said. “We both did. It’s intention… to take over the bodies of Humans, use their flesh as food for its… spawn.”

“It wants to use humanity to incubate its young,” Turner continued. “It… made a mistake. It intended to land in the great lake… where it could loose those worm things in what would be the water supply of hundreds of thousands of people. It was trapped in this lake within the lake until we….”

“Monstrous,” Dreichsler said. “Monstrous. To use people in that way… to try to destroy humanity for its own means….”

Turner looked at the German soldier as if he was about to say something. Rory had taken in breath ready to berate Dreichsler about the way some Humans had used other Humans in all those concentration camps across Europe. There were men who called themselves doctors who had done far worse to the poor unfortunates in those places than the alien creature planned to do. At least the alien did it to live. The Nazis had far less excuse.

Then he remembered that Dreichsler was just a young man from Dresden. He wasn’t Gestapo or SS. He probably didn’t even know what was happening in those camps. Even if he did, what could he do about it? If he had protested in any way he might have ended up in a labour camp himself.

Dreichsler understood that it was wrong to do things to humans that made them less than Human. He was the sort of German the world needed in the years of making amends that were to come, soon.

“I’m just thinking,” Rory said. “When I gave you two sedatives, the worms were dead before I extracted them. Medicines meant for Human consumption kill them. Enough of them would kill the parent creature.”

In the back of his mind, Rory could hear The Doctor talking about unique species and how genocide was the worst crime in the universe. But he didn’t know if this creature WAS unique. He DID know that its intention for the Human race was a worse one than the Nazis ever envisaged. He had to take action to destroy it.

“Do we have enough sedatives?” Turner asked.

“Not here, no,” Rory answered. “I brought basic medical needs for two dozen people. But we can signal to the shore. We’re not marooned here, after all. We can call in the troops.”

The signal was a distress flare in Rory’s medical kit, in case of extreme emergency. He hadn’t used it before because he felt he needed to know what he was dealing with before he exposed anyone from the mainland. Now he knew the danger lay within the water. As long as they kept away from it, they were safe.

The flare was answered within an hour by the coastguard. The camp was evacuated by boat and within an another hour they were all back at Pine Camp where Rory placed everyone who had been affected in the sick bay for observation and made his report to the commander.

“And they dealt with the alien straight away?” River asked.

“No,” Rory answered. “They thought I was bananas. They were about to have me carted off to the army psychiatric unit when they got a phone call from the White House.”

“The White House?” River was impressed as well as surprised. “How come?”

“Because I called Winston Churchill,” Amy answered. “It took a couple of hours to get a call put through across the Atlantic, but in the end I got through to his secret War Time Cabinet rooms in the London underground. I told him about the alien. He called Truman. Everything happened very quickly after that, I can tell you. They dumped about four tons of sedatives in the lake on Calf island. It killed the alien stone dead. I’m not sure what happened to it afterwards, the alien I mean. The lake recovered and there are fish in it now and birds nesting and everything. I think they freeze dried the alien and put it in a warehouse at Area 51 or wherever the Americans keep things like that.”

“And the whole story was buried under a million tons of secrecy,” Rory added. “It was the first officially known alien to land in America, predating Roswell by two years, but nobody knew about it except me, Amy, three US soldiers and twenty-four Germans.”

“The good news was that Dreichsler got to stay in America on account of it,” Amy continued. “They all did. They were given US citizenship in return for their silence and since Germany was in such a mess they all took the offer. I think the government thought it was safer to keep them here where they could pick them up if they talked, but none of them did. So it all ended well in the end.”

“Sounds like a satisfactory result to me,” River agreed. “You don’t know the real consequences, though. I came across it in the course of my archaeological work. Klaus Dreichsler… in about two years time he’s going to marry Sergeant Turner’s sister and they’ll have two sons. One of them will have a son of his own in the course of time, and he’ll grow up to be the man who developed a way of making it rain in deserts and drought conditions, ending hunger on this planet.”

“Seriously?” Rory and Amy looked at their daughter in surprise. “I mean… that’s not you winding us up?”

“It’s not. In fact, the Dreichsler catalysing method is still used in the fifty-first century to create the right weather conditions on colony planets, allowing the Human race to spread out across the universe. It’s the reason we could expand beyond this planet at all. So, father, dear, when you saved Klaus Dreichsler from a nasty death, you did more than you thought you did.”

“Wow,” Rory said.

“Wow,” Amy echoed. “The Doctor would be proud.”

“No kidding,” Rory answered her. “But he’d pretend not to be impressed just so that we don’t get too full of ourselves.”

“Yes, he would,” Amy agreed. River grinned and raised her coffee cup in toast.

“I’ll make him impressed. Don’t you worry. I have ways.”

Rory and Amy decided they didn’t want to know what those ways were.