The Master, in the guise of Professor Thascalos, has constructed at the Newton Institute in Wootton a device known as TOMTIT - Transmission Of Matter Through Interstitial Time - to gain control over Kronos, a creature from outside time. The creature is summoned but proves to be uncontrollable.

• BBC
• Jon Pertwee
• Katy Manning
• Roger Delgado
• Nicholas Courtney
• Richard Franklin
• John Levene
• Ingrid Pitt
• Wanda Moore