On the surface, it's just a slight variation of Ghost with the gender of all the key characters changed. Reese Witherspoon is a workaholic doctor who is now in a coma after a car crash. Mark Ruffalo is a loner who moves into her apartment, and runs into her "ghost".

The variation is that he can see and talk to her, but of course, no one else can. The other twist is that the "ghost" Reese has no idea who she is, and why she is that way. As far as she knew, she just got home and found a stranger in her house.

They slowly unravel her identity with the aid of Jon Heder, who plays a spaced out clerk at a supernatural bookstore. And they are pressed for time; an evil colleague of hers is all set to pull the plug.

On the whole, quite a nice movie with the heart-warming ending that generally accompanies movies of the genre. Long story short: you can watch it once.