Mawdryn Undead:

10ep 1,2 – The door to the Headmaster's office doesn't fit its frame very well! There's a very obvious wedge-shaped gap above the door when it's closed, through which light can be seen.

20ep 1 – When the Doctor and Turlough are about to leave the TARDIS to disable the transmat signal on Earth, the Doctor accidentally knocks against the door lever, which starts slipping down, and he has to move quickly to pull it back to the 'up' position.

30ep 1 – After the Doctor and Turlough leave the TARDIS, Tegan and Nyssa carry a couple of small stools into the console room and sit down facing the camera. This seems pretty unremarkable, until you realise that in this shot the camera is taking the place of one of the console room walls. So from Tegan & Nyssa's point of view they've both just sat down directly facing a blank wall. Why would anyone do this??

40ep 2 – When Tegan and Nyssa drag Mawdryn into the TARDIS, Tegan jogs the console with her shoulder, causing it to move out of position a little.

50ep 2 – In Turlough's dream sequence with the Headmaster and the Black Guardian, the shots of the sleeping Turlough in the middle of the sequence show the pillows in a completely different position to those at the beginning and end of the sequence.

60ep 3 – When Turlough is telling the Black Guardian (referring to the TARDIS console) "I can operate it if you show me how!" he slams his hand down on the console hard enough to make it wobble hugely back and forth.

70ep 4 – Standing in the TARDIS doorway, the Doctor tells Turlough to find the Brigadier and transport him in the capsule, then quickly turns to rush back inside. Unfortunately for Peter Davison, he forgot that only one of the police box doors was open, and he slams straight into the edge of the closed left-hand door!
[Ouch...]

80ep 4 – While talking to Turlough in the TARDIS, the Black Guardian appears to spit on himself.

Add a new blooper for this story »