A/N: This is my first New Tricks/Doctor Who crossover (no, I don't know how I thought of it either!) so any feedback would be hugely appreciated.
Disclaimer: I don't own Doctor Who or New Tricks.
He wasn't certain how it had happened, exactly. Which was unusual, because he was the Doctor, and he knew everything. Or at least he pretended to. But he was glad that it had happened in this way. He was glad that the very last regeneration of the Doctor had made him a human, a quiet man with a brilliant mind (but Northern, again, why?!) He'd chosen to deviate from the standard John Smith alias on his first night as his final self. He no longer needed an alias. This was him, this was it. So he selected the name Brian Lane, the first name because he liked it and the surname because, well. All lanes came to an end at some point.
Anyway, the name wasn't the difficult part. Neither was tracing a wonderful girl by the name of Esther, whom he'd once taken to see the fifty moons of Felix. They had watched from the safe vantage point of the Tardis as the moons disintegrated beneath them, slowly melting into the blackness of space. He'd instantly liked her because she hadn't done the whole squawking 'it's bigger on the inside' whilst running around the Tardis thing. Although she was a grown woman now, and less inclined to go along with his schemes. But she still had that typically human sense of adventure, and they were married within a year. He enjoyed being married, not least because Esther wasn't half as infuriating as River. It gave him a sense of normality, and he soon found that the rest of his life slotted into place nicely, a steady job, even a son.
Until he messed it all up. He wasn't certain how that had happened, either. The alcoholism. How could he have succumbed to something so pathetically human? The answer was complicated, really. He was stupid to think that this was going to be easy. The real question was how could he ever forsake his old life for a simple human one, how could he forsake two hearts for one, how could he never time travel again, how could he give up his beloved Tardis? That was why he had turned to alcohol. He was two people trapped in one body, a time lord trapped in a human life.
But then something unexpected had happened. If there was one thing he'd learnt, after all these years, it was that humans were unpredictable, and Sandra Pullman was no exception. She had taken a chance on him when he was at his lowest, and she had turned his life around, along with Jack and Gerry. A widower and a womaniser. Not the company he would have originally selected, but there it was again. Unpredictable. And so he had reached his endpoint. Human, with one heart (and Northern) but happy.