Fight Club (1999): Ending Explained

An unnamed, sleepless office worker (the Narrator) meets a charismatic soap salesman named Tyler Durden. After the Narrator's apartment is destroyed, the two start an underground fight club that grows into Project Mayhem, a cult-like organization planning to attack the credit-card companies that hold society's debt. The twist: Tyler is not a real person. He is the Narrator's split personality, and the Narrator has been running Project Mayhem himself. In the finale he shoots himself to kill Tyler, and he and Marla watch as the buildings explode.