In this romantic comedy/drama set in Dublin, Ireland, 11 interwoven sad stories of 54 characters — mostly unhappy, unlikable and mean-spirited — demonstrate how the actions of one can affect the lives of those around him. When a boy named John (Cillian Murphy) breaks up with his girlfriend Deirdre (Kelly Macdonald) in order to test her, his plan backfires, leaving her upset and him alone and miserable. Unbeknownst to him, his actions have set off a chain of events that cause lives to collide. John quits his job at a supermarket to join Lehiff (Colin Farrell), a thief looking to pull off one final, big heist. Trying to win back his girlfriend through a series of bad choices, he makes matters worse, and the aftermath continues. Entering the plots are Detective Jerry Lynch (Colm Meaney), an amateur boxer and an aspiring TV producer.
The film begins in a confusing jumble of storylines, but it gradually ties them together. Adding to the confusion is dialog in a strong Irish accent that includes words unfamiliar to an American audience. There are also several sex scenes, including implied self-gratification, and a lot of bathroom humor. In several cases, consequences for bad behavior are realized. A few positive messages are overshadowed by the immorality, graphic violence and pervasive bad language, making this film highly non family-friendly.