The Master Tin
Colony in Space
The Time Lords discover that The Master has stolen secret files revealing the location of the dreaded Doomsday Weapon. They summon the Doctor out of his exile on Earth and send him five centuries into the future to the planet Uxarieus to retrieve and safeguard this vital information.
Arriving on Uxarieus, the Doctor and Jo encounter a group of Earth colonists whose very existence is under threat due to falling crops and low morale. Representatives of the ruthless Interplanetary Mining Corporation are disputing the colonists’ claim to the planet.
Their only hope is placed on the imminent arrival of an Adjudicator from Earth to resolve the dispute. Meanwhile, the Doctor pursues his mission, but first he must deal with giant lizards, killer robots, and deadly primitive tribesmen – knowing all the while that The Master cannot be far away.
original air date : 10 April – 15 May 1971
The Time Monster
A new device called TOMTIT – the Transmission Of Matter Through Interstitial Time – is being developed At The Newton Institute at Wootton. TOMTIT is the creation of the enigmatic Professor Thascales. A “life-long pacifist,” Thascales refuses on principle to dine with a party of invited observers that includes Brigadier Lethbridge-Stewart of UNIT.
The Doctor soon suspects that TOMTIT is another of the Master’s dastardly schemes. This time the Master hopes to use the device to gain control over Kronos – the legendary chronovore that feeds on time itself.
The secret of TOMTIT’s power is a fragment from an ancient trident-shaped crystal used by the High Priests of Atlantis. When TOMTIT proves too weak to harness Kronos, the Master journeys back to ancient Atlantis to retrieve the main crystal. While UNIT forces are kept busy repelling invaders the Master has sent from past eras, the Doctor and Jo pursue the Master back to the dangerous last days of the doomed civilization
Colony In Space was the fourth story of season 8 and The Time Monster was the fifth story of season 9.