100,000 BC When two schoolteachers stumble into the TARDIS and meet the mysterious Doctor, they are whisked back in time to the stone age where early man is attempting to make fire. The Mutants (AKA The Daleks) When TARDIS lands on the planet Skaro, the Doctor's determination to explore leaves the travellers stranded when the ship's fluid link is taken by the robot-like Daleks. Their only hope of retrieving it is to encourage the pacifist Thals to fight the Daleks.