Faithful unto death

Obito Uchiha had thought he was done with the part of his life that consisted of hunting criminals. He had thought he could turn his back and walk away, never to be bothered again by the institution he had given his all and that had broken him beyond repair.
But once a member of New Scotland Yard, always a member of New Scotland Yard.
And when old enemies rise again, can he really stay away, or had it always been temporary?
Then there's also the silver-haired Detective Inspector that won't leave him alone.

Alternative Universe - Canon Divergence