Revealing: When Kaftan is activating the revitaliser controls you can see Patricck Troughton moving into position for when he runs and grabs her.

Revealing: In this Doctor Who story, there is a fight scene between Toberman and the Cybercontroller. The Cybercontroller uses a very visible harness to lift Toberman over his head,and the wires attached to the harness Toberman is wearing are also very visible...and when Toberman, in return, lifts the Cybercontroller above HIS head, it is obvious that what Toberman is lifting is an empty costume, with no-one inside it.

Revealing: The Cybermen retreat into their tombs backwards; this was achieved by simply having the film of them coming out of their tombs run in reverse.

Factual error: When the group divide up into parties, the leaader says they need to be at the rocket at 1630, so meet here at 1625. He then goes on to say that will give them an hour to look for anyone that's missing. The other actors seem to notice his mistake because they either look puzzled or look off camera, probably seeing if anyone would shout "Cut."

Revealing: When Jamie and the Doctor try to open the doors to the tomb, watch them push it with their feet.