Doctor Who, the time monster

Outside the bounds of this world lives Kronos, the Chronivore - a mysterious creature that feeds on time itself. Posing as a Cambridge professor the Master intends to use Kronos in his evil quest for power. To stop him, the Doctor and Jo must journey back in time to Ancient Atlantis and to a terrifying confrontation within the Time Vortex itself. But can even the Doctor save himself from the awesome might of the Time Monster?