The best moments of the movie's first two-thirds or so (it's pretentiously divided into segments called "Heaven," "Earth" and "Hell") come from Rush as a sort of junkie elder statesman, a chemistry professor who takes Dan and Candy under his wing and provides them with some homemade heroin when they're short on cash. Three guesses what happens to him come the third act.
Once Dan and Candy try for the first time to get clean, the movie starts becoming too histrionic for its own good, especially in a shameless hospital scene right out of an anti-drug video. Ledger and Cornish retain their grips on the reality of their characters, though, even if director Armfield doesn't. By the predictably downbeat wrap-up, there's little to be gained, for the characters or the audience, aside from the obvious: Just say no.