Doctor Who: The Time Monster (TV)

The Master has constructed a device known as TOMTIT - Transmission Of Matter Through Interstitial Time - with which to gain control over Kronos, a creature from outside time. The creature is summoned but the effect proves uncontrollable, so the Master flees. The Doctor shuts TOMTIT down but the Master later reactivates it, using it first to ensnare Krasis, High Priest of the lost city of Atlantis, and then to attack UNIT forces by way of a series of timeslips. The Master takes Krasis back to Atlantis in his TARDIS in the hope of stealing the sacred Crystal of Kronos, with which he aims finally to dominate the creature.