'Stay out of –' As the Doctor disappeared in mid-sentence, Rory took a careful perch at the base of the Pandorica. He was overtaken by a desperate wish that he hadn't been so arbitrary in sending the Doctor away. Now that he was alone it hit him just how long this was going to last. He placed his sword on his knee and leaned his head back against the Pandorica. When he remembered the Doctor's idea to jump forward in time, panic flooded through him. It stole his breath and made his plastic heart race in an unpleasant way. Still, he wasn't going to leave. It wasn't conceivable for Rory to leave Amy alone for so long; why didn't the Doctor understand that? Amy got stressed if people deserted her even for an afternoon; she would go mad if she had to live with her own company for centuries. Memory hit him like a club. No, Amy wouldn't go mad because she couldn't feel it. Amy was – no, Rory shook his head, refusing to let that idea sink in. Mostly dead; she was only mostly dead – he had to keep repeating it to remind himself that there was hope inside that box. At the end of this long, mad journey he still had a dream to live for. Amy – brilliant, vibrant, alive Amy – was reduced to this, but there was still hope. That was something to cling to. Rory would stay with her, would assuage some of the guilt he felt at having done this to her. She was in the box because of him; he had failed to overcome his programming and now Amy was shut away from life, but she remained a beacon: the prize of her renewed life beckoned at the end of the two thousand years of darkness. Rory shuffled a little as he settled into the task.

Looking back, the first day was the longest. Before the Doctor had left, staying with Amy had seemed like the best idea in the world. Rory was plastic; he could survive anything. He would live two thousand years guarding the box, then be reunited with Amy and the Doctor and everything would be wonderful. It had sounded so simple when he was defying the Doctor's 'No, Rory. No.' When he'd made the decision he hadn't really thought about the time involved. The enormity of all those years – all those days, minutes and seconds – weighed down on him now he was alone. Time, which had always seemed so swift, slowed down to a trickle and the impact of what he was doing slammed home. Grimacing, Rory refocused on the future. The point of doing this was to get Amy safely to a time where she would be able to wake up, and his best weapon for surviving it was his hope. Closing his eyes and dreaming of the moment when he would see Amy again, Rory leaned back against the Pandorica.

He hadn't really understood, when the Doctor said he'd go mad – but after several days without sleep, he started to work it out. Time was already folding in on itself and Rory couldn't remember if this was day ten or day fifteen of the several hundred thousand he had to see through. It didn't help that he was underground; day and night had no meaning here and there was an eerie sameness to each day in the underhenge. The fossilised memories of now-extinct aliens surrounded him, their useless weapons forever threatening the Pandorica. They were a constant reminder that he could never leave Amy alone. Too paranoid to leave her even long enough to see the sun and find out what time of year it was, Rory sat in the same position day after day. Eventually, he moved his limbs and the plastic creaked a little from the unaccustomed usage. That would never do. If someone or something came in and attacked the box he needed to be able to respond, to defend Amy. He started going outside each day and walking around the perimeter of the henge to keep his joints mobile. He tried, each time, to convince himself that the 'never-were' could do Amy no harm but always breathed a sigh of relief when he returned to his underground home.

Soon, too soon, they were discovered. It may have been one year later, or it may have been ten, when the Roman legion in the camp below decided to investigate the henge. Rory would rather have stayed down there, hidden for the whole two thousand years, but the Romans viewed him as a deserter. To allay their suspicions he allowed them to take Amy from under the earth, but he felt waves of anxiety at the idea of anyone else touching her home. He made sure he had his hand on the Pandorica at all times, reassuring Amy that he was still looking out for her. Staying with her during the Roman years became Rory's hardest task. He was a Roman; he had all their memories and all their battle skills – they wanted him to use them. Talking the leader into believing he had a mystical calling to protect the box had been difficult, though with his Roman pre-programmed memories Rory was able to dredge up the name of a minor goddess who had appeared to give him the mission. Being a superstitious culture, the Romans had allowed him to accompany the Pandorica when it was taken back to Rome after he demonstrated, with the proper use of entrail reading, that he was fated to guard the box for the span of his life.

His life settled into a routine. He sat by Amy's side during the days and took to walking around the environs at night. He stopped calling the Pandorica a prison because that seemed so cold and harsh; instead he focussed on the hope it contained. He renamed it her enchanted castle in his head; it was sustaining Amy –his sleeping beauty – and keeping her safe until the evil spell could be reversed. Since he couldn't be the one to restore Amy to health – couldn't play the role of the handsome prince who woke her with a kiss – Rory remained steadfastly by her side, protecting her.

Rory didn't eat, couldn't sleep and struggled every time he had to talk to the gawking masses who came to see the magical box during Rome's festivals. There were so many festivals in Rome it felt like there was a new one every second day, but not one of the many gawpers cared enough to ask him what was in the box. Not one of them cared that Amy was there, waiting. Eventually, they stopped coming and the Pandorica lay forgotten among all Rome's other spoils, with Rory alongside it. He began talking to Amy; spending his time recounting the minutiae of the days. It wasn't very interesting, even to him, but he kept doing it so he could feel connected to her; just in case she could somehow hear and remember and know someone had been there with her. After a few years he began to tell Amy stories. At first he recounted all the games they had played together in their half-remembered childhood in Leadworth; the childhood that fought with his Roman background for space in his head. Then his stories became fanciful fairytales of sailing away to the stars with his sleeping beauty and her raggedy Doctor. He told Amy about the planets they had visited and the adventures they'd had.

Sometimes he thought he could hear her laughter in response. Whenever that happened he always jerked up, hope coursing through him in case she had somehow managed to escape already, in case he'd already made it through the two thousand years. Always, it was a phantom and Rory sat down again, heart dejected as the time stretched out before him again – endless oceans of time. He knew he was going mad, knew the Doctor had been right about that, but couldn't bring himself to care. He just patiently went on oiling his joints, doing a daily (or maybe twice daily, or weekly, or maybe even monthly) walk around the building they were housed in.

Amy's voice cut across Rory's thoughts as he oiled his gun hand one day a couple of hundred years after the Doctor had left him alone. 'What are you doing that for, you numpty?' she said, and Rory raised his head quickly to look into her eyes. She looked so real, so beautiful with that teasingly downcast look she wore when she wanted something from him. He stared at her for a few moments, forgetting even how to speak, before reaching out to cup her face. Just as his hand was about to touch her cheek she disappeared making Rory clench his fist, shamed that he had thought she might really be there.

The next time Amy appeared, Rory was patrolling outside the stone warehouse where the Pandorica was stored. He felt a whisper tickling at his neck and he turned his head to find Amy grinning at him the way she always did when she had fooled him about something.

'You're not real,' he muttered, his tone bitter as he turned his back on her. Immediately, he regretted his decision and turned back to find her but she had already vanished. Rory clenched his fists again and trudged onwards, executing a perfect military turn at the next corner to take his mind off his foolishness in banishing Amy.

'That looked good; I do love a squaddie,' Amy's voice teased him from the shadows and Rory stopped and stared at her, mouth open. 'Don't gawp, idiot,' she laughed at his consternation. Somewhere deep inside himself Rory knew this wasn't real, but he still took the opportunity to spill out all the guilt and shame he'd been holding in for centuries.

'I'm sorry,' he pleaded. 'I'm sorry. I – I didn't mean to.' He gulped and looked into Amy's eyes. She was smirking back at him, but holding his gaze. Encouraged, Rory continued. 'I shouldn't have been mad at you. I was mad at you, you know, for forgetting me. But then ... I made it so much worse. I'm sorry,' he repeated. He stopped and took a deep breath of air, trying to focus himself onto the important part. 'You won't forgive me, I know that. How could you? I failed.' His shoulders slumped in defeat as he added, 'I should have fought harder, should have tried harder not to –' He couldn't bring himself to say the words, to tell Amy to her face that he had killed her and risk seeing her disdain and rejection. Telling the Doctor was one thing, and even his 'Oh, Rory' still haunted Rory; telling Amy was impossible so he whispered, 'I'm sorry,' one last time then stopped, looking to Amy for direction, trying to figure out what she needed him to say next. Through his whole apology, Amy had smiled that secret, knowing smile that meant she was humouring him. When it became obvious he wasn't going to say anything else she said, 'shouldn't you be off guarding me?' Rory's mouth dropped open in horror. Terror flooded through him as he realised how long he'd been standing there without giving one thought to the real Amy in the box inside the building. He ran back towards the door and checked the Pandorica thoroughly, twice, to be sure no-one had disturbed her while he was distracted. The dream Amy had disappeared when he started running and it was several years before she returned. After that, however, she was his almost-constant companion, alternating insults and loving words; maddeningly close yet fading away every time he forgot himself and tried to touch her.

The next few hundred years passed in a flash of images, over-exposed in Rory's memory like a bunch of old polaroids. Each one took root in his mind; the framework they all created was the only thing holding up his fragile grip on himself, on what connected him to humanity. Each memory was an integral part of the reality he built for himself: some were stark and dark – standing out in the foreground of his mind; others faded away almost to insignificance but still lay there on the edge of his consciousness. When he began to feel lonely Rory would stop, sit back against the Pandorica and flip back through the growing list of things he had seen and done. Time itself blurred around him and he couldn't keep track of the years he lived through, let alone the thousands of individual days. Those faded memories were all he had to keep him on his path to resurrecting Amy and he clung to the growing pile.

Rory had a vague memory of the Franks arriving in the middle of a raid on Rome, and having to run them off with his sword. When that didn't convince them, he'd scared them off with his carefully oiled gun hand. Whispers of the Lone Centurion had started to drift down to him around the same time and he would smile to himself. Masonry began to collapse around him as the building he and the Pandorica were housed in fell into gradual disrepair. Rory took to polishing the box every day, worried that the stirred up dust would harm the Pandorica. He made sure the deep marks in the body were as sharply defined as ever. They became a symbol to him: if he could keep her enchanted castle perfect, then Amy too would be perfect when she awoke.

He kept talking to her, telling her the stories that swarmed into his head. Amy would sit perched on the side of the Pandorica and listen intently, making the occasional correction if he went too far into flights of fancy in the stories she already knew. He told one where he fought a dragon; he was almost certain it had happened sometime during the endless years he'd guarded the Pandorica. The image of the huge beast looming overhead as he ran his sword through it was so clear compared to the washed out memories of other moments in his life, but Amy would roll her eyes when he brought it up and he stopped telling that story. There was another tale where he single-handedly battled every villain the Doctor had ever told them about; Amy approved of that one, sitting there with eyes shining as she listened to him.

Rory laughed, the sound humourless in the dank darkness surrounding them. When they were children, it had always been Amy telling the unbelievable stories about the valour and heroic deeds of the Raggedy Doctor. Now, it was Rory desperately inventing – or was it recalling? – stories for Amy where he slaughtered all her foes. His stories always involved him defending Amy to the death because through it all, through the madness and the loneliness and the boredom, wove the knowledge that he was the one responsible for Amy's imprisonment in the box. The thin fiction that Amy was in an enchanted sleep was fading and Rory's guilt grew as the days passed. He had to live with the brutal knowledge that even though he had spent his whole life trying to protect Amy, he was the one who had caused her ultimate destruction. So he kept telling her stories of heroism and hope, trying to push away the feeling that he didn't deserve to be thought a hero.

As the fairytale of his sleeping beauty faded away, Rory descended further into madness. He became only vaguely aware of his surroundings. Sometimes they were in a museum; other times they were left to rot somewhere in a forgotten cellar in a new city. Once, he was pretty sure that someone told him he was now the property of the Knights Templar but the time he was with them in an ornate church flew by in an instant and he soon forgot about it. Always, he scared people if he ever tried to open up to them; the legend of the Lone Centurion had developed mythic proportions and some people saw him as a harbinger of doom to the city. Whenever disaster was imminent, he always appeared dragging the Pandorica to safety, and superstitious people began to think he caused the disasters. Many tried to kill him, to get rid of the evil that sightings of the Centurion always signalled; they always failed, having discounted the crucial 'fire in his hand' part of the legend.

Rory began to cultivate his infamy. When people began to come visiting just to take on the famous centurion, the wildness in his eyes and his fierce determination to keep the Pandorica closed would scare them off. Most people avoided him due to the power of the stories that rose around the Pandorica, but every hundred years or so Rory would have his chance to slay another beast for Amy – metaphorically, of course. He never actually killed any of the fools who disturbed them but he certainly made sure that none of them returned and that the box remained safely closed, the thin thread of his hope still anchored inside it.

Through the whole journey, the memories Rory had sunk into the box grew deeper. They twisted through his thoughts until Amy was the only thing that seemed real to him. He had been worried that over time he would lose track of the import of what he was doing along with the loss of his sense of self, but that never happened. Amy was always in front of him, her laughter bubbling around him, sustaining him. After a while he didn't care that the Amy who kept him company, teasing him, calling him idiot and numpty, and looking at him with that heart-stopping clear gaze, wasn't real. He didn't care that people were afraid of him; he didn't even care that he still had several hundred years to live through. Rory's memories of the real Amy, trapped in her dreamless sleep, slowly faded away leaving the fantasy of Amy in their place. As he polished the symbols on the Pandorica, with the dream Amy perched nearby critiquing his methods, Rory was almost happy.

Eventually, he realised that he had to start living in the real world. Looking at his cracked and peeling armour he decided that maybe more time had passed than he'd thought. He knew that for over a thousand years he had kept the armour shining, and for it to have fallen this far into disrepair he must have neglected it for far too long. He took stock of his surroundings. He and Amy were in a museum, so late one night Rory broke into the staff areas to find himself some clothing. He found a dull brown suit that caused him a momentary ache as he thought of the Doctor and his offer to jump forward through time. He remembered again the stark horror that the idea of leaving Amy alone had caused him and wondered what had happened to that Rory – the one who was filled with fire, passion and righteous indignation. The moment of lucidity passed and Rory refocused on the dream Amy who was admiring him as he quickly dressed in the new clothes in preparation to go outside the next day.

Blinking as the sunlight dazzled his eyes, Rory grabbed a man who was crouched down nearby sucking on a cigarette, and asked him what day it was.

'February 19th,' the man said, looking at him as if he had escaped from Bedlam. Rory grimaced as he realised the man was closer to the truth than he cared to admit.

'What year?' he asked urgently. Whether it was the intensity in his eyes or a certain reckless air of danger about him, the man stood abruptly and hurried off without replying. Rory sighed. His sketchy memories of history class told him that he was in the twentieth century but he couldn't be sure when. The other people scurrying around him avoided his eye in a way that was so careful it must have been deliberate. Rory didn't want to call attention to himself by confronting anyone else so he began to walk too. Soon he was swallowed in the crowd and an indefinable tension had left the people on the street. Unwilling to get too far from Amy, he turned a nearby corner. In one niche near a building was a newspaper stand. Peering through the glass in the front he was able to make out the date. February 19th, 1940. The headline suggested that he was in London. Rory's history class memories surfaced again, giving him the uneasy feeling that sometime in the next year London was going to be bombed.

The knowledge that so much time had passed, that there were only fifty years left of his vigil, made Rory feel dizzy. He had let so much time flow past without noticing, and it shamed him. He had wallowed in his madness and in doing so had made Amy more vulnerable. While he had communed with his dream Amy, the real one had been relying on him and he hadn't delivered. That he had been lucky so far – that he hadn't had to fight any real demons during that time – was a fluke and Rory determined then and there to find himself again. He would defend Amy from the Blitz when it came, then he would disappear as the Centurion forever. He had played that role for too long and lost sight of himself. The last thing he had said to the Doctor all those years ago was that he had to be more than human because he wasn't human. Over time he had lost sight of that, lost sight of the knowledge that Amy had fought hard to help him connect with his humanity. Before the end she had forced him, through the sheer strength of her personality, to be Rory Williams rather than Rory the auton. He had allowed time to pass in a rush because it was easier that way, but he'd lost himself again in the process. That was no way to honour Amy. The Centurion needed to retire so Rory Williams could return as human as possible for this last stretch.

That was easier said than done. Rory kept the suit he had borrowed and, after making sure that several people saw the Lone Centurion drag the Pandorica to safety in the Blitz, he wore it to apply for a job at the museum. The problem, as it had been with the Roman legion so many lifetimes ago, was convincing the management that he should be allowed to stay close to the Pandorica. The National Museum was new and the still slightly wild look in Rory's eyes made the caretakers nervous. However, his obvious love and care for the Pandorica and surrounding artefacts swayed them in the end and he was allowed to guard the museum after dark. During the days he would wander the halls talking to people, the effort painful as he gained back the ability to interact with others. Always, he would return to polish the Pandorica, give it a pat and say hello to the Amy locked inside before starting his shift wandering the musem.

Rory watched as the oceans of people visiting the museum changed around him. The sombre formality of the Forties gave way to the exuberance of the fifties and sixties and the long hair and bellbottoms of the seventies, then the eye-watering colours and teased hair of the eighties. In amusement, Rory saw people from Leadworth he had grown up thinking of as old come through the museum first as children, then as teenagers and young adults. The older they got, the happier Rory became. This was his time now – these people lived in the world he had known; he could feel the time shifting as the world inched closer to the day that Amelia would set Amy free. On one heart-stopping occasion he saw his parents, obviously early in their relationship, giggling and snuggling together as they stared up at the huge Pandorica. With hungry eyes on them, Rory wondered if he existed in this starless universe, and if so how many years he was from being born. With a pang that these wonderful people might never know him, he dragged his eyes back to the Pandorica and Amy. He had to concentrate on the future she represented rather than allow himself to wallow in the could-bes of his possible life.

Instead of the long, slow slog the middle ages had been, the twentieth century was passing in a blur, and it felt like a mere blink of his eye from the end of the eighties to the night when Rory returned to the Pandorica's room after a patrol to find one of the 'footprints of the never-were' had woken up and heard a familiar voice trying to talk it out of attacking him. His hand dropped open and he shot the dalek before really paying attention to what that voice meant. His heart leapt at the thought that his long journey might be over now that the Doctor was there. If he was there, then Amy, who had waited so patiently for so long, would soon be out of her confinement. Rory's sleeping beauty would soon awaken. Then, in a small group of figures running towards him, he saw her and time, which had been passing so quickly just moments before, slowed to a crawl.

'Amy,' he cried, almost convinced that this was another of his hallucinations even though he had known through his entire journey that this day was coming. The hope that this final time she might be real rooted him to the spot. Rory couldn't even breathe while she closed the distance between them. He thought he heard his own name as she approached; then she was in his arms and he was clinging to her as tightly as he could. She wasn't disappearing, and that meant his vigil was over. He was babbling apologies again and she was telling him to shut up and kissing him like her life depended on it and he was losing himself in her, in the amazing aliveness of her. That two thousand years had all been worth it. Amy – brilliant, vibrant, alive Amy – was in his arms, and she was ignoring everyone but him. The guilt that had overwhelmed him for so many years was driven away in a flash by Amy's fierce passion, by the fact that she was as caught up in him as he was in her. The knowledge that Amy forgave him was outshone only by the miraculous understanding that he, Rory, really meant as much to her as she did to him. The power behind that thought almost knocked him over, and he was only able to stay upright by clinging to Amy. Love doesn't always feel like this, he thought; love isn't always this overwhelming in its overabundance, but he didn't care. The world was reduced to the two of them, yet it seemed to encompass the whole universe. On the periphery of his mind Rory could tell that someone was trying to advise them of danger surrounding them, but he couldn't make himself care. All that mattered was this one eternal moment of love and fulfilled hope – and Amy.