Homicide detective William Somerset (Morgan Freeman) has just seven days left to retirement when he is paired with his brash replacement David Mills (Brad Pitt). The pair investigate the murder of a man who has been force-fed until he burst, then that of a rich lawyer made to cut a pound of flesh from his own body and consequently bled to death. The fact that the word 'greed' is written in blood on the carpet leads Somerset to speculate that they are dealing with a serial killer who is using the seven deadly sins as a blueprint.