Unicorn, a team of ancient heroes, protects the world from an ominous force. When an evil force looms on the industrial, revolutionary streets of London, the members of Unicorn accidentally awaken in the bodies of teenagers. Melinda, a powerful sorceress, Seng, a cosmic monk, and Edred, a warrior elf, have lost their memories and their magical abilities have weakened. With the help of their steam-powered robot Copernicus, they must unravel the mysteries of their past and present in order to defeat a timeless threat.