Rose didn't know what Peter had been expecting to hear.

Any planet beyond Earth would be impossible to reach given current technology made it possible for humans to only get as far as the Moon. But hearing the name of his world and species for the first time had sparked something within the lieutenant. It was more than he had ever known about himself in his entire life, more than he'd ever thought he could know.

It was enough to turn anyone's head.

"Peter?" Stefan ventured. "Are you…"

Flinching as he came out of his own thoughts, Peter's voice sounded much higher than usual and unconvinced of what he was saying.

"I'm fine. Just a bit of shock to hear it. Why did… Did something happen there?"

"I don't know." The Doctor admitted. "You being here in the first place is quite impossible."

"Could there have been a war or something?" Rose asked. "You know, like Superman? Maybe the planet…"

The way in which Stefan scowled at her as he shook his head made Rose shut herself up. Flushing red with embarrassment, she knew exactly why the corporal didn't want the conversation to proceed any further. The reason why Peter had been sent to Earth, and how that had happened might not be as honourable as protecting him from a conflict or a world on the verge of destruction. From the way the Doctor had described it, Valerus sounded like a very peaceful and well-established planet with no problems to warrant sending a child away from it.

"Well, no. There hasn't been a war there for… Oh, about a thousand years." The Time Lord confirmed, scratching his head. "Nimarians are a very proud people. They have a temper on them though, so don't think that anger of yours is unique. I've certainly learned my lesson not to cross you lot, that's for sure."

The attempt to make a joke fell flat.

Peter wasn't even trying to hide the crushing sense of bitterness and resentment as he realised that he had been sent away from a life and a possible family he would never get to know without even getting the reassuring knowledge of a why.

"I see."

Stefan empathised with his friend's pain.

"Peter, whatever happened. It doesn't change anything." He told him. "Who you are isn't defined by where you come from, mate."

Though Peter nodded in agreement, the kind words did nothing to bring him any comfort.

Why? Why had he gone and asked about something he'd been quite happy living without? His parents had told him pretty early on that he had been adopted, and it had never been an issue that had caused any problems. They had raised him and loved him as though he was their own.

The only thing they had failed to do was to tell him the exact circumstances of how and where it was they had found him all those years ago.

That had all changed just one week after his sixteenth birthday. He had transformed for the first time and they had all learned the truth about what he was. It hadn't stopped him living his life, however, and neither had it damaged his relationship with his parents or Stefan and Emma. They had all stuck by him, keeping his secret hidden better than he ever could have done on his own.

But with this new information came the sudden desire to erase knowing it in the first place.

Pushing away such unwanted thoughts and feelings was easier said than done. They were clinging to him like a bad smell and it was a struggle to focus back onto the job in hand, particularly Jane Wilson and her urgent need of a swift evacuation to the surface.

"We need to go." He decided. "Our extraction plan… We've got to get Jane out of here. She needs help and we have to get back to base."

"Sorry it wasn't the news you were looking for." The Doctor remarked. "But the strange thing is -"

"Doctor, that's enough." Stefan stepped in. "Peter's right, we need to get out of here."

His tone was as serious as his face. It was warning the Time Lord not to say another word on the subject, lest he risk facing the corporal's wrath. Peter had been hurt by what he had found out and he didn't want any more damage to be done from discussing the matter further.

"We'll split the vest and packs between us." Peter continued. "I'll carry Jane back, we should reach our entry point in less than an hour given we know the way through now."

"What about Karugon?" Rose pointed out. "Are we just going to leave him here?"

The lieutenant glanced over at the unconscious alien.

"No, we can't." He said. "Not when he could still pose a threat to people. We'll have to take him with up with us, hand him into UNIT for processing."

"But he looks like you." Stefan pointed out. "What if he can do the same things you can? UNIT aren't stupid, they'd figure out where he learned it from."

It was true that Karugon might be able to transform in a wolf… Well, a Nimarian wolf as it should really be called now. But Peter knew that they didn't have much of a choice. Morally, he couldn't just walk away and let the creature run amok in the New Forest. Despite his actions, Karugon had also lost his entire family in one night.

"It's okay, we'll find an explanation. We always do." He assured his friend. "Maybe the Doctor can take him somewhere he'd be safe?"

"Safe?" Stefan questioned. "You do remember when he was threatening to break my neck?"

"Just as clearly as I remember him breaking my leg. We follow the rules, Stefan. We show him mercy and hope that he can learn from it."

The Doctor smiled at the lieutenant.

"Couldn't have put it better myself." He told him. "I'd be happy to take him off your hands. Might need an escort though, just for the journey."

"We can arrange that once we're back at base. I'm sure UNIT can spare a couple of squaddies to make sure it's a smooth trip." Peter agreed. "Some of them would be happy to volunteer. Travelling in the TARDIS is on a lot of people's bucket list."

"Is that so?" The Doctor mused. "Why don't you come along yourself? You know the prisoner and afterwards, we could always go and see… You could come and…."

It wasn't often that the Time Lord struggled to find the right words and his hesitancy prompted suspicion as Peter's brow creased into a frown.

"Are you suggesting that I go to Valerus?" He questioned. "You want to take me there?"

The Doctor seemed surprised that Peter was reacting to the offer with hostility. Realising that he might have made a mistake, he attempting to brush the whole thing off as a casual remark as he blew out a deep breath and shrugged his shoulders in response.

"Don't you want to? You might find some answers and -"

"You just don't know when to quit, do you?" Stefan snapped at him. "Now enough is enough, Doctor. We need to get out of here."

He was angrier than Peter was, enraged that the Time Lord was daring to defy him and continuing to pour more salt into the wounds he had already inflicted. But offering to take Peter away in the TARDIS to uncover a Pandora's box of his long-forgotten past had been the last straw and was something that the corporal simply wasn't going to tolerate.

"Sorry, Stefan. But this isn't your choice to make." The Doctor stated. "Peter shouldn't be on Earth in the first place. It is impossible."

The two soldiers looked confused.

Perhaps it had never occurred to either of them that the likelihood of Peter making it to this planet was so slim. They also worked for an organisation that put them in daily contact with creatures and species from across the universe and maybe because of that they had lost any notion of strangeness or improbability at such encounters.

"What do you mean?" Peter asked. "How is it impossible? I came here in a spaceship, I already told you that."

"I've seen it," Stefan confirmed. "A big round silver one with one door that has a porthole window. There's still a big crater in the woods behind his house from when it crash-landed."

"Didn't anyone notice?" Rose asked. "Someone must have seen something like that?"

"I live in the middle of nowhere, Rose," Peter explained. "But it also happened to be Bonfire Night and my parents passed off the damage as a stray firework. The next morning my dad dragged the ship into his shed and it's been there ever since."

But the Doctor knew that this was only the concluding part of the story. Somewhere in-between Peter leaving Valerus in his vessel and arriving on Earth something had happened that was quite beyond anything he had ever encountered before.

"What you're describing isn't a spaceship." He said. "I know this because the Nimari species won't have them for another five hundred years. The escape pod you travelled here in can't even make it from one end of the planet to the other, let alone get you to Earth."

Peter shook his head at this.

"Escape pod?" He asked. "An escape pod belonging to what?"

"The only form of aircraft Valerus has. Try to imagine a large clipper ship with sails infused with solar-panels. Valerus is quite a sunny planet, you see. But they're pretty rare and aren't normally used for public transportation." The Time Lord replied. "The pods are designed to drop off the side of it and fall straight to the ground. No engines, no controls. Nothing in which to pilot it with."

With more questions than answers coming at him, Peter couldn't even imagine what had transpired all those years ago. He'd only been three months old when he had left Valerus, so why was he on a ship in the first place? More pressingly, however, how did a pod not designed for space survive the journey to Earth with him tucked safely away inside it?

Something Kalagan had said suddenly echoed back to him.

"The creatures here told me that they were in travelling in space and were suddenly transported down here." He told the Doctor. "It was some kind of electric storm and…"

The Doctor was quick to reject the idea.

"Highly unlikely." He declared. "They were in space already and are from several hundred years into the future. You might be a long way from home, but you haven't travelled through time, Peter. Also, you'd have still been on Valerus. That storm wouldn't have been anywhere near you."

"You know that for certain, do you?" Stefan challenged. "Lightning could have struck twice. The lightning the creatures described -"

"Might not have even happened. They were probably wrong about what they saw, lost and confused because -"

"How can you say that when you weren't there yourself?" The corporal continued to argue. "Doctor, you're very clever, but maybe you don't know everything."

The Doctor took the remark like a personal insult.

"I'm Time Lord, Stefan. There's isn't much I didn't know, especially when it concerns time travel. Peter hasn't travelled in time, because if he had then I would have picked up on it when I scanned him earlier and -"

"You scanned me?" Peter accused. "When? Why were you -"

"Because I was curious!" The Time Lord shouted over him. "Goodness me, Peter. I thought you were smart enough to realise that by now. Haven't you learned anything from tonight? Then again, maybe you're happy living on Earth in complete ignorance?"

He regretted the words as soon as he said them.

Peter was actually very clever and it was certainly not his fault that he had grown up not knowing anything about his heritage. Neither had he been given the choice of leaving Valerus in the first place. But the damage had already been done and what little respect the lieutenant had acquired for the Doctor vanished in an instant.

"Well, I'm glad I could elevate your boredom for one night, Doctor." He said in a surprisingly steady voice. "As for your… offer. I'm going to have to decline."

Stefan jumped in before the Doctor could open his mouth to speak.

"Don't say anything else." He growled. "Not one more word."

Burning with questions and information he'd not yet shared, the Time Lord looked to Rose in the hope that his companion would take his side on the matter. But she caught his eye and shook her head at him.

"Best not." She said. "Let's just go."

Her words were like a trigger.

Stefan took it upon himself to walk over to the pile of equipment that had been left by the spaceship. Kneeling beside it, he began to take stock and ensure that the large backpacks were ready for the journey back up to the surface.

Peter had gone to retrieve his gun from where he had dropped it after Karina had grabbed him.

He wasn't surprised in the least when the Doctor followed him over. The Time Lord wasn't going to give up just because they were telling him too, he was far too stubborn for that.

The Time Lord also wouldn't quit until he'd gotten to say everything that was on his overworking and overstimulated mind.

"What do you want, Doctor?" He sighed wearily. "Because I am tired and it's been a hell of a day."

"I know." The Doctor acknowledged. "But if it was me, I would want to know what happened."

"Well you're not me, are you?" Peter bit back. "Look, I'm glad you told me what I am and where I come from, Doctor. Really, I am. But what is the point going back to a world I've never known? Twenty-three years might be a short amount of time for you, but it's been a lifetime for me. Valerus isn't my home, Earth is."

"Valerus is in your blood. So is being a wolf and -"

"Stop saying wolf like you know what it's like to be one!"

Peter's eyes turned yellow again as his Nimarian temper ignited.

Once more, it was Stefan who calmed the situation down. Leaving the equipment where it was, he came running over and put himself between the Doctor and his friend. Nothing was said about it but he was making it clear that he wouldn't allow the discussion to continue any longer.

"Peter and I can manage Karugon between us." He said. "Doctor, you carry Jane out whilst Rose carries my backpack. I've already put everything we're going to need into it."

The Doctor thought about arguing back but Peter was already walking away, heading off in the direction of Karugon.

The alien had become less than an afterthought given all that had been going on. Stefan had knocked him out with a single blow and he was going to be a heavy load to carry all the way back. Still, at least he wasn't awake to cause any more trouble.

"That's fine, Stefan." Rose agreed. "We're happy to help. Aren't we, Doctor?"

The Doctor merely hummed in response. He was still staring at Peter.

"Well, you don't have much of a choice," Stefan replied. "Now, we're going to struggle to get up that hill. But if we're careful then… Peter, look out!"

It wasn't clear at which point Karugon had woken up.

Between fighting Karina, finding Jane alive and the revolutions and ensuing arguments which had followed, nobody had realised that the alien had just been pretending to be unconscious.

Peter was knelt right next to him when the creature made his move.

He struck the lieutenant in the temple with a solid left hook, sending him crashing to the floor. But Karugon did not attempt to flee and instead choose this moment to enact his revenge on the person who had ended the lives of his brother and aunt.

Peter had barely hit the ground before Karugon grabbed the back of his shirt and lifted him up and off of the ground. The alien's knee collided with his chest and he was dropped again. Winded and bruised, Peter was dimly away that Stefan was shouting something.

"Karugon, stop! Stop right now or I'll shoot!"

Stefan had retrieved his gun and was holding it firmly out in front of him, the barrel pointed squarely at Karugon's head. The creature still looked like his best friend, but to Stefan it didn't matter. He wasn't fooled and wouldn't allow Peter's life to be put at risk by any hesitancy on his part.

Stopping his assault, Karugon twisted around to face him.

But even this small distraction was enough for Peter. With newfound strength, he leapt to his feet and drew out his gun. He didn't want to use it, there had already been too much bloodshed tonight, yet he wasn't about to give the alien room to try anything else.

"Karugon, look at me." He said. "Stop now and we can -"

The creature lunged for him before he could say anything else.

Unprepared, Peter didn't have a chance to bring up his gun and they were suddenly locked into a battle for it as Karugon grabbed hold of his wrist as he tried to wrestle it from him. Peter tried to pull back, but their strengths were even now, and Karugon had not spent the last nine hours fighting against a pack of homicidal predator bats.

BANG!

The gun went off as a bullet was fired straight into the air. Peter felt the weapon slip from his grasp and knew it was now beyond his reach. Distracted, he wasn't watching his footing and tripped clumsily over his own feet. Karugon fell with him and landed on his chest, knocking the breath out of Peter once again.

Another gunshot ran out and suddenly the alien reeled back, howlingly in pain as he clutched a bloodied shoulder.

"Ah!" He roared. "Pathetic human!"

Stefan advanced towards Karugon a little more as he kept the gun he'd just fired aimed at him.

"Last chance, Karugon." He ordered. "Get away from him and surrender yourself!"

The alien hissed and jabbed an accusing finger down at Peter.

"He killed my family!" He wailed. "He deserves to die!"

"It's true, I am responsible for their deaths," Peter admitted, holding his hands aloft as he lay on the ground. "But, believe me. I didn't want it to go down like this."

"Then why did you do it!"

Slowly, so as to not at agonise Karugon further, Peter got back up onto his feet.

"They all died trying to murder people." He said. "I had to stop them."

"Why? Why do you care for these people? You're not even human."

"Neither am I." The Doctor said, stepping forward. "But Peter and I… We consider this planet to be somewhere we can call home and we want it and its people safe."

He exchanged a look with the lieutenant and was pleased to see him nod back in acknowledgement.

"Karugon, I get it. You feel compelled to do things because your family do them too." Peter continued. "But being something doesn't have to define you. There's a balance you have to find between who you are and who you can be. Killing as they did, that doesn't have to be you."

"You're going to kill me if I surrender." Karugon accused. "Aren't you?"

"Karugon, I could have killed you twice over by now," Peter told him. "But I haven't because I know you can be better than this. But you want proof of my word, fine. Stefan, holster your gun. Put it away right now."

Stefan did as he was told without hesitation. Understanding the gesture of goodwill Peter was trying to achieve, he put away his weapon.

"What is this?" Karugon spat. "What trick are you playing on me?"

"I'm not," Peter replied. "Come with us now and no harm will come to you. We can even get you off this world, somewhere you can start anew."

The Doctor nodded in agreement as the lieutenant looked over at him expectantly.

"Yes." He said. "I can take you anywhere in the universe. If that's what you want?"

Rose held her breath as she watched the alien appear to ponder over the Doctor's offer. Mercy seemed to confuse him. His aunt hadn't exactly been the loving maternal kind, and maybe this was the first time he'd been shown a genuine kindness.

"What I want..." He began, looking up at Peter. "Is your blood!"

Peter's hands had been held up in surrender and he'd had no chance to defend himself. Pushed to the ground, he felt Karugon's hands close around his throat.

Gently, as though he was enjoying what he was doing, the creature began to squeeze and Peter could feel himself slowly being strangled as he flailed his arms around uselessly, blindly searching for something solid to grab onto.

Seconds became a lifetime, but his finger suddenly closed around the cold carbonised metal of his gun.

The weapon had landed just inches away from him, and Peter didn't even think about it as he slammed the handle into the side of Karugon's head. Feeling his crushing grip instantly relinquish itself from around his neck, Peter lashed out with his fist and jerked his body up at the same time so that Karugon was unbalanced and stumbled away from him.

With the last of his strength, he staggered to his feet and took up a combat stance before delivering a powerful kick to the alien's chest. The strength of the blow sent Karugon flying through the air and the creature came crashing down several meters away.

The two rucksacks he landed on cushioned his fall.

"You think this is over!?" He cackled with delight. "You haven't got the strength left in you to stop me."

Peter knew that he was right.

He was too tired to transform into a wolf again and he would never be able to bring Karugon down in the same way he had with Karina. His only options were the gun in his hand or try one last time to negotiate with the alien.

But seeing the black skin begin to spread over the creature's face made the choice clear for Peter.

"Twice I could have killed you, Karugon." He replied. "This makes three, and on this world, that's all you get."

If Karugon found his choice of words strange then he didn't time in which to try and make sense of them. Peter's gun swung up and a single gunshot was fired. For a moment, it was as though time itself had frozen still.

Karugon and the two rucksacks vanished, consumed by a ferocious explosion.