Attack of the Cybermen, Part Two

As the TARDIS lands on Telos, the Doctor becomes a prisoner of the Cybermen, whilst Lytton and Peri become allies of the Cryons, the inhabitants of Telos, who want Lytton and his partner in crime from Earth to steal the Cybermen's space shuttle so that they can all escape the Cybermen's plans to destroy both Telos and Earth, and to Peri's horror, they have no intention of freeing the Doctor.