Earthshock

The Cybermens' mouth/chin pieces were originally clear plastic, but were later sprayed lightly with silver paint. Due to the order of filming they tend to swap back and forth.

Watch the scene when the last soldier in the search party hears a noise down in the caves and turns around. By the time he does so, the androids have disappeared down a side corridor, but you can see the shadow of one of them on the cavern wall. The soldier would have had to have been blind to miss it.

Just before he receives a message saying that the freighter has received security clearance the Cyberleader tries to press a button on his console - and misses! But we hear the appropriate sound effect anyway.

About 15 minutes into the episode, as Tegan complains that she's exhausted and Scott tells her to keep her voice down, look in the shadows behind them - something that looks like a stick is being waved around in the darkness. Then immediately afterwards as they climb the stairs on their way to the bridge you can see what could possibly be someone holding a clipboard moving about in the background. (This information came from Peter Davison, the first person to spot it afterwards.)

After one of the first battles, as the Cybermen are walking up some stairs through the dead bodies, one of them stumbles briefly.

During the cliffhanger it's blatantly obvious that the 3 columns of advancing Cybermen are merely mirror images - watch the middle one's right hand disappear!

Look at the scene after the troopers and Tegan are separated. The troopers return to the TARDIS. There are four of them remaining at this point: the commander, a male with straight hair, a male with curly hair and a female. As they enter the TARDIS a Cyberman grabs the female trooper. In the next shot (inside the TARDIS) the commander, the male with straight hair and the female make it inside, closely followed by the Cyberman, but the curly-haired male trooper is missing! After they leave the TARDIS and are evading Cybermen in the freighter's hold, the female trooper has disappeared, and the curly-haired male one is back...!

As the Doctor, Tegan and Nyssa are being led away from the bridge, the Cyberleader loses his footing when he gets to the bottom step.

Watch Adric as he's trying to type in the final code on the keyboard. He keeps tapping a key or two, then pulling away from the console because Matthew Waterhouse knows it's going to blow up any minute, thanks to the final remaining Cyberman (which Adric isn't supposed to know about.)

Matthew Waterhouse leaves (dies) at the end of the story.

After Adric's death the end titles to Part Four scroll over a shot of his shattered badge with no end theme.

Part Two includes a flashback sequence with clips from Logopolis 1, The Tenth Planet 2, The Wheel in Space 6 and Revenge of the Cybermen 3.