When we first meet Donnie he appears like any other Eighties college boy - he has dinner table fights with his sister Elizabeth (Gyllenhaal's real-life sibling Maggie) and hurtles through the neighbourhood on his bike. Then things take a slightly different turn. A jet engine weighing several tons crashes through the roof of the family home, completely obliterating his bedroom.
Fortunately, Donnie has been tempted out of the house by a six foot rabbit, resplendent with huge pewter teeth and a grim warning that the world is going to end. Jimmy Stewart's Harvey, he ain't.