The film explores several themes, including justice, morality, and the darkness that lurks within human beings. Through the character of John Doe, Fincher critiques the societal norms that we often take for granted, and the consequences of allowing evil to go unchecked.

: They hunt a meticulous serial killer known only as "John Doe" (Kevin Spacey).

Eventually, John Doe walks into the police station and surrenders. He offers to confess to all the crimes, but on one condition: he must take the detectives to the location of the final two bodies.