First, I have to point out that this is the last movie starring Brittany Murphy that was released in her lifetime. She was excellent in this excellent movie, and I hope she knew it. Another reviewer here on Amazon has stated that she is in only '15 minutes' of the movie. That's completely untrue. She is one of the three main actors in this film -- she played a major role, and did it very well. Her appearance is not just some kind of cameo.
That said ... There's a story about this story, and it's worth knowing before you watch this movie. Alex Merkin, the director, had an idea ... a sort of noir / 'locked room' hybrid, and it is one hell of a great plot. If James M. Cain, Jim Thompson, or especially Cornell Woolrich had written this story back in the day, Fox or RKO would have snapped it up (and Otto Preminger would have directed) -- "Across the Hall" would have made Noir and Hollywood history. The story really is that good. (The role cell phones play in the movie ... really the only modern element ... could easily have been replaced with another plot device -- car keys, notes, whatever -- and probably should have been, to keep this great plot truly timeless.)
I think Alex Merkin knew what he had with this story back in 2006, when he and screenwriter Julien Schwab developed the story into a 16-minute short, also called "Across the Hall." Virtually every line and scene in this 16-minute masterpiece also appears in the 'long' version, released in 2009. And the 'long' version, which is the subject of this review -- and also is written by Schwab and directed by Merkin -- doesn't just expand on its 16-minute predecessor, it improves on it in every way.
This isn't 'neo-noir,' as with a modern film that borrows elements from that genre. No, as stated above, this is something that Cornell Woolrich could have written in 1940, if he'd thought of it. "Across the Hall" would fit comfortably in any vintage film noir anthology -- except it's in color and was made a half-century after the golden age of 'classic' film noir. Even "Chinatown" (I film I love, a lot) doesn't have, and doesn't try for, the claustrophobic, heart-pounding sense of minutes slipping away as fate closes in on the hapless protagonists -- and that's the basis of all classic film noir.
In case you can't tell, I love this film!