"'Gehenna" is the second episode of the first season of the American crime-thriller television series Millennium. It premiered on the Fox network on November 1, 1996. The episode was written by series creator Chris Carter, and directed by David Nutter. "Gehenna" featured guest appearances by Robin Gammell and Chris Ellis.

The first season of the serial crime-thriller television series Millennium commenced airing in the United States on October 25, 1996, concluding on May 16, 1997, and consisting of twenty-two episodes. It tells the story of retired FBI Agent Frank Black. Black has moved to Seattle, Washington with his family and has begun working with a mysterious organization known only as the Millennium Group. He investigates cases with members of the Group and the Seattle Police Department, contributing his remarkable capability of relating to the monsters responsible for horrific crimes. He finds that his daughter has inherited the same "gift" that he has, while the cases become increasingly more personal.