Two broken people manage to stumble upon each other. Both need each other, whether the realize it or not. She will bring his Bad Wolf back, and he will help her realize The Chosen One has been standing there all along.
Post Doomsday for Doctor Who, post first Wizarding War for Harry Potter. Remus Lupin was in such a sorry state after losing all of his friends, he was thinking about drinking himself to death. But then a mysterious man called the Doctor shows up in his flat, and tells him just how much his life is worth living for.
The similarities of Sirius' death and the loss of Rose.