Another adventure for everyone's favourite time-traveller. Answering the Brigadier's space/time telegraph, the Doctor (Tom Baker), Sarah (Elisabeth Sladen) and Harry (Ian Marter) arrive in the village of Tulloch, near Loch Ness. A series of attacks have taken place on local oil rigs, and many are blaming the legendary monster. The Doctor discovers the creature to be the Skarasen - cyborg pet of invading aliens the Zygons. Their own planet having been destroyed and their spaceship crippled, these deadly shape-shifters are now intent upon taking control of the planet Earth.

All six episodes, including two that are animated due to their being missing from the BBC archives, of the second Doctor's classic 1967 adventure. In 'The Ice Warriors', the Doctor (Patrick Troughton), Jamie (Frazer Hines) and Victoria (Deborah Watling) arrive on Earth in the year 3000 AD - in the middle of the second Ice Age. At the Brittanicus Base, a team of scientists struggle to control the elements with a machine known as the Ioniser. When a body is found perfectly preserved in the ice barrier which surrounds the base, it is thawed out. The creature proves to be an Ice Warrior - one of an agressive reptilian race from Mars, intent on awakening its fellows and conquering the Earth.