A fateful landing on Earth in the 26th Century finds the TARDIS deep within a system of subterranean caves and even deeper within the mystery surrounding the brutal murder of a group of geologists working there. Who is controlling the androids guarding the hatch in the rock face? More importantly, what lies beyond the hatch?

The answers provide a serious threat for the Doctor as the time and place is set for an encounter with his old arch enemies. The Cybermen are well and truly back and the Doctor and his companions could well be counting the cost in truly personal terms

These stories originally shown. 08/03/82 - 16/03/82

Producer: John Nathan Turner
Directed by: Peter Grimwade