Jack Harkness was sitting in a pub in London, his first time on earth since the 456, personally speaking, though he was in 1999 according to his vortex manipulator. He didn't care. In fact he didn't care much about anything since Ianto's death. He had walked into it when he noticed that it was covered by a sort of perception filter.
He walked inside, bought a pint and glanced around the room. Apart from the barman, there was only a young man with black hair and astonishing green eyes and a red haired young woman who was talking to him. Jack watched, interested as the young woman finished speaking and as the young man nodded listlessly in a manner Jack recognised from many a soldier who has been thrust into a particularly traumatic incident within maybe the last year or two, depending, and thus isn't quite on the same wavelength as everyone else. The red head smiled sadly, kissed the young man on the cheek, provoking a half smile from him and walked out the back door. As she passed him, Jack thought about flirting, then saw the engagement ring on her finger, and there was a look about her that meant she was not to be trifled with.
Jack guessed she was engaged to the listless young man sitting and staring at his drink. As the barman went to his backroom on some errand of his own, the young man said in a quiet but carrying tone, "Have you ever died? Or wished you could when all your friends were being killed or tortured?"
Jack raised an eyebrow. This was a strange conversation starter by any standards, yet Jack mulled it over, then answered, "Yes and yes."
The young man turned to look at him with a slightly disbelieving expression, as if he had not expected an answer.
He said abruptly, "Really?".
Jack smiled and was about to give a jokey reply, when he remembered all the people who had died. Owen, Tosh and Ianto. All three deaths he felt were his fault.
When he looked up again, he saw the young man staring at him with eyes that were not unlike the Doctor's to Jack's eyes. They both had old and compassionate eyes in a young face, but the Doctor was 905 years old, whereas this man was no more than 21 at a push.
Jack smiled, though his heart wasn't in it, and said with fake levity, "How did you die?"
The man's eyes took on a faraway look and he said, "I was murdered by a man who had tried to kill me since I was 15 months old. When I was 17 he succeeded. Briefly, anyway."
Jack raised both eyebrows. "How did you come back?" he asked, genuinely curious.
The man thought for a moment, as if thinking about where to start.
"First things first, I am a wizard, and I believe you are a muggle."
Normally Jack would have started laughing, but the man had said the sentence in utter seriousness, and Jack had heard rumours. After all, it would explain the perception filter, or whatever it was.
The man carried on. "I guessed you were a muggle because very few wizards wear anything even vaguely resembling muggle clothing if they can avoid it, and none carry guns, especially not revolvers", he said gesturing to the holster at Jack's waist.
"Wizards are a sort of society within a society, with our own laws, mostly regarding magic use and our own Ministry which makes these laws." Jack noticed the man was talking with a slightly glazed expression as if his mind was elsewhere. "Most muggles can't see the leaky cauldron, though we have had problems from a bunch called UNIT. Gung ho bastards the lot of them, though the caps are nice. I managed to get hold of one for Ginny." At this point the man was smiling ruefully, though is expression turned to surprise when Jack started laughing loudly.
"What's so funny?" He asked cautiously.
"It's nothing. I was just after one of 'em for my partner." Jack's smile faded. "He's dead now. Because of me."
He took a deep gulp of his beer. "I have seen friends die right in front of my eyes. I have seen them tortured in unimaginable ways. Hell I've been tortured in unimaginable ways. I think I know how you feel."
"Anyway, I was prophesied to kill Lord Voldemort," At this, there was a crash from the backroom as if the barman had been shocked into dropping something. The young wizard glanced at the door to the backroom then continued. "So he decided to kill me. However my side found out, and placed me and my family under a spell, a sort of very powerful perception filter. You couldn't see it unless you knew it was there. It required a secret keeper. The first choice was my parents best mate Sirius Black, my godfather, but he suggested another friend of my parents, Peter Pettigrew also known as Wormtail."Jack noted that the young wizard spat these last words in tones of utter loathing."Only my parents and Sirius knew of the switch. But Pettigrew was spying for Voldemort-" Again, there was a crash from the backroom and a muffled yell.
The young wizard continued his story. "Voldemort killed my parents on Halloween and tried to kill me, but my mother had died to save me, and somehow gave me some extremely powerful protection. So powerful that the killing curse failed and rebounded, turning Voldemort into something less than a spirit. Soon after Pettigrew found my godfather and confronted him in the street, acting as if Sirius was the traitor, then blasted half the street killing over a dozen people, and cut off his own thumb, making it look like Sirius had murdered him."
Jack listened to this with mounting horror. In all his years he had never heard anything like it.
"Sirius wasn't given a trial. He was sent straight to Azkaban, a prison guarded by Dementors. He spent 12 years there."
Jack sucked air through his teeth sharply. Dementors he had heard of and come across. How could anyone make someone live in close proximity to monsters like that?
The young wizard, never one to miss things, looked up with a bitter smile on his face and said, "I take it you've met them then?"
"Yeah, I can see them."
This shocked the young wizard into silence. After a few moments he ventured, "How?"
"I'm not your average muggle. I'm immortal for one thing." Jack rejoined offhandedly.
The young man's eyes narrowed dangerously, but when he spoke his voice was neutral with a hint of steel. "How did you become immortal?" Spitting the word immortal like it was made of acid.
"I used to travel with a man called the Doctor, well he wasn't human, he had two hearts and if he was about to die could regenerate, basically change his looks and some of his personality, but he looked human so who cares. He was in his 9th incarnation back then, and totally brilliant, and he and his other companion Rose somehow made me a better person. It sorta rubbed off on me I guess," Jack said with a grin, "But we ran into trouble on a satellite called the gamestation in the year 200100. It was being manipulated, and in turn manipulating the Earth, by creatures called the Daleks, mad mutated monsters that lived inside a metal battle suit which looked sorta like a pepper pot. They had one electronic eye, a weapon like a plunger and a small death ray gun. I heard about them before, and one day they were the biggest threat in the universe, the next they disappeared
"The Doctor's people, the Timelords, had gone to war with them, the last Great Time war. It lasted God only knows how long since both sides used time travel and one civilisation was destroyed before it was even created!" The young wizard was looking ever more incredulous, yet not disbelieving. Jack carried on, "From what the Doctor told me, he had an extremely powerful weapon called the Moment. It destroyed the Daleks, but at a price. It killed all the Timelords as well. Well, not quite all, but that happened later. But one Dalek emperor survived, and fell through time. It created a new Dalek race out of the dregs of humanity.
It created 400,000 monsters that hated themselves, 'cos Daleks hate everything not Dalek, a bit like outta space Nazi's and they were made out of humans. They worshipped the emperor as a God and were mad. They attacked the gamestation, and the Doctor used his time machine to send Rose home, so she would be safe and the Daleks wouldn't get hold of the TARDIS and all its power. I was shooting the Daleks with some other defenders, but we might as well have thrown at 'em. I was the last man standing, and they killed me. They then advanced on the final room where the Doctor was building a Delta wave. It woulda killed all the Daleks, but everyone on planet earth as well. He couldn't do it, and as they were about to kill him, the TARDIS came back. He had turned it off, but the TARDIS is sentient and has telepathic circuits, so Rose looked into the heart of the TARDIS. It made her omnipotent." The young wizards green eyes grew wider, understanding. "She destroyed all the Daleks, and brought me back to life. She couldn't control it, so I guess the Doctor took it, 'cos it was killing her. They left me behind, but I had a time machine of my own, well it was a sort wrist band thing. I aimed for 21st century, but overshot and ended up in 1869. I died plenty of times, but I always came back. I'm Captain Jack Harkness, the man who can never fully die."
The young wizards eyes sparkled as he grinned, properly grinned for the first time in over a year.
"I'm Harry Potter, the boy who lived."
Jack got up, leaving his money on the bar, also smiling. "Good talking to you Harry. Look after that girl of yours, cos she looks like she'll look after you."
Harry's face creased into a dry smile and he said, "Don't I know it. Good speaking to you Captain Jack."
Jack saluted with a grin and walked out the Diagon alley door as Ginny came through. As he passed her he winked and said, "Howdy ma'am! Now you look after your fiancé d'ya hear?" And he strode out, with a new spring his step, leaving behind a very confused Ginny Weasley.
"Harry, who was that?" she demanded.
He smiled, stood up and kissed her gently, and whispered in her ear, "The man who made me feel better."
28 years later
Harry waved as his children got on the train and the train left the station. As he turned back towards the exit, Ron and Hermione having gone ahead, or more accurately Hermione had dragged Ron off to Flourish and Blotts so he could carry the books she was getting, he saw a familiar face, with a familiar cocky grin on that face. He took Ginny by the hand and said, "Want a drink Captain?"