Detention is the punishment at Foxfire. Keefe is a frequent visitor to detention, as is Sophie (who is sometimes there because of Keefe). It takes place during lunch, in a glass pyramid that is one floor below the principal's office. The Detention Hall is very gloomy because it has a low ceiling and the windows block most of the light. Any mentor can assign a prodigy to detention. Prodigies can be given detention for just one day, or for several weeks or more. Every day, a different mentor leads detention, and give the prodigies an (often unpleasant) task. Essentially, it serves the same exact purpose it would serve in the human world: to punish misbehaving prodigies.

Some of the mentors and their detentions include: