A young man leads a pretty humdrum life assessing car crashes to determine if his automobile company should issue recalls to fix problems. He also suffers from insomnia and takes to attending group therapy sessions for people who have survived various diseases. There he meets Marla who like him attends these sessions though she is neither a victim nor a survivor. His life changes when he meets Tyler Durden on a flight home. Tyler seems to be everything that he's not and together they create a men-only group for bare-knuckle fighting. It soon becomes all the rage with fight clubs springing up across the country and the group itself becoming an anti-capitalist domestic terrorist organization. Tyler and Marla develop a relationship leaving him often on the outside of what is going on. He soon finds that the group is out of control and after a major self-revelation decides there is only one way out.