Disclaimers: I don't own any the characters used for this story, nor am I making any profits out of writing this fic. In stead all the credit for these wonderful characters goes to the creators of Harry Potter, Torchwood and Doctor Who!
Spoilers and changes: HP: All Seven books to I chose to disregard anything H/G related and Hermione died in the final battle (as much as I love her I felt that it was needed for this story).Torchwood: All seasons (although I still haven't watched all I will use info I find online as well so I thought I better warn you)
Great chunks were still missing from the marble staircases of Hogwarts, parts of the balustrades were gone, and bloodstains occurred on ever few steps, stains not even magic seemed able to erase. Years had passed since the end of the war, yet the stains had remained. They were faint and barely visible to the naked eye, but if you knew that they were there you could still see their faint outlines. The windows that had been broken during the final battle had been replaced, but even after three years some of the missing pieces of the castle marble stonewalls and staircases remained just that, missing. Harry didn't know why; perhaps the castle's magic prevented the repairs somehow, perhaps the school simply lacked the funding, war was after all a very costly affair. Or maybe they had been left as they were intentionally, as a reminder to the students and the world of what could happen if one did not keep ones eyes, ears and mind open.
The reason for Harry's visit to the school had of course been to see Neville. They had gotten closer after the war, though there was still a few secrets Harry felt the need to keep from the other man, if only for his own protection. For how would Neville feel if he knew that he was indirectly responsible for the state his parents had found themselves in or that he just as easily as Harry could have been the baby Voldemort personally had went to kill all those years ago. No, like Dumbledore Harry knew that there was many things in this world that were best left unsaid.
As he was about to leave he was stopped by a stern voice calling out for him.
"Mr Potter" While her tone at one time would have made him nervous, it now brought a smile to his lips.
"Professor McGonagall" He said as he turned around to face her.
"Where are you going?" She asked disapprovingly.
"And this is what stopped you from coming up to greet your old professor?" She asked, looking at him expectantly.
"I apologise, Professor." He smiled.
"Come, have a cup of tea before you leave"
"Of course. Who am I to refuse the Headmistress of Hogwarts?"
No more than minutes after the tea had magically appeared the professor spoke with directness he both wished that Dumbledore had had and was grateful that he had lacked at the same time.
"You are leaving us."
"What makes you say that, professor?" Harry asked, calmly taking a sip of his tea.
"I have seen what you are doing, though no one else seems to."
"And what would that be?"
"You are saying your farewell, I won't try to stop you. But where are you planning to go?"
"Have you had me followed?" He asked casually but she knew it was noting casual about the question at all.
"I don't need to, all I need to do is open the paper." She looked concerned.
"Ah..." He smiled, a smile not unlike that knowing smile the former headmaster used to give her.
"What are you planning?" She asked, though she already knew he wouldn't answer.
After Harry finished his farewells to his world he literally chose to step into another. Not even when he had walked to his death during the war had he been so nervous, so uncertain, so scared. Then he had known what awaited him; death. When he stepped through the veil in the department of mystery he didn't know where he would end up. He might just die, as the unspeakable believed. But Harry had thought differently.
When researching Horcruxes he had stumbled across an interesting passage about rifts in time and space. The passage wasn't about the rifts themselves but rather on how to keep one open, and how to control it. It was a dark ritual requiring human sacrifices in loads, using their very souls to keep the rift open and guarded. Only those who had seen death caused by magical means could hear the tortured souls as they to tempt them to pass though. After which they will try to tare you apart, forcing you to stay and help them preform their duty, hence even after the ritual was completed it was beyond risky to pass through.
A dark wizard created this particular veil back in the late 1200's as an escape route before he began his war, creating the many legends surrounding the veil before he himself had passed though it to keep people from following him. Harry could only hope as the world on his side of the veil aged so had the one on the other. Strangely enough he wasn't worried about the warning or the spirit guards or even that he may not be able to return. He hadn't even considered whether there would be arch on the other side or not. Instead he felt like he imagined most people felt before going away on their first around the world trip. He was exited and he could barely wait.
Walking through the veil had been painful, worse than any curse he had ever experienced and the only thing that greeted him on the other side was a basement, a plain and empty basement, in the heart of muggle London.
Never would he have thought that just a few years down the line he would be spending his days chasing Aliens and words such as Weevil, Time lord and spaceship would become part of his daily vocabulary.