On the same night as a bus accident kills four people, Thomas is born. And he spends his childhood being able to see and talk to the ghosts, that is until he is told that he needs to give up his "imaginary friends", so they stop showing themselves.

Fast forward twenty (or so) years. The ghosts find out that they were attached to Thomas so they could get a chance to finish their unfinished business.

RDJ really shines in this as he plays his role, but also has to take on the mannerisms of the four actors that play the ghosts.