Michael McCrea (Cillian Murphy) owes €1,000 to the biggest, nastiest gangster in Dublin, Perrier (Brendan Gleeson). Michael is flat broke and has 24 hours to pay. If he misses his deadline, the gang will punish him by breaking a limb (and the longer he takes, the more limbs they will break). Desperate for the money, he seeks financial aid from "The Mutt" (Liam Cunningham) who is known as a criminal lender. Things become complicated, however, when his estranged father Jim (Jim Broadbent) and his secret crush, Bren (Jodie Whittaker) become involved, and when Bren shoots and kills one of the gang members who was sent to deliver his first punishment, Perrier forsakes the money owed and instead puts out a €10,000 bounty for Michael and Bren.