The crew enters a dimension where magic works and an ancient grudge is held against humans.
The Enterprise is pulled into a region where the laws of physics change, and the crew meets Lucien, a being with powers who tells them that magic works there. Lucien has a grudge against humans because of how his kind was treated on Earth, and the crew is put on trial.
The story features beings that look like figures from legend, and a trial that has overtones of the Salem trials. Kirk must argue for the crew's innocence. Fans remember the striking visuals and the way that the setting allowed the animators to display imaginative creatures.