In the film, Ronan (Wahlberg and Weisz's daughter in the film) is murdered, and the film looks at her attempt to work out how to get to Heaven (she's trapped between Heaven and Earth), while Wahlberg and Reisz deal with her loss on Earth.
I think most people will like the film. It drags in places, but in the main it tells a decent story. That having been said, I found the film hard to watch in places, though that might be because I've lost my family. There's a certain amount of anger balled up in me still, and I didn't really see that in either of the characters, which irritated me no end. I felt like yelling "Why aren't you angrier?" at the film sometimes.