Ghosts of Hamilton Street (2003)

In this award-winning student film, a troubled writer questions his sanity as people in his life vanish without a trace - and it seems he's the only one who realizes it. Each disappearance catapults him into a version of the world in which that person never existed at all, and once he realizes the specific order to this phenomenon, he must try to save the people he loves from forces he may never understand.