Revealing: When Lytton stabs the Cybercontroller, some of the Cybercontroller's 'blood' gets splashed on the camera. (The 'blood' is green-dyed water spraying from the Cybercontroller's arm.).

Plot hole: The junkyard at 76 Totters Lane seen in 'Attack of the Cybermen' was also in 'An Unearthly Child'. If you consider London's high land value, it is highly unlikely that an ownerless junkyard would still survive twenty-two years....the local authority would have long since issued a "compulsory purchase order."

Plot hole: The energy weapons in this story fire a series of small red bullets, which cause numerous problems. For a start, the guns appear to have seven chambers, yet the bullets start from the same point; as they are separate bullets, surely the most minor of movements would mean they wouldn't emerge in a straight line. Later, when the Doctor steals a cart, the bullets are coming quite a distance towards the screen but the bullets don't get any bigger. Also, in the same scene, the Doctor passes through the area they seem to be travelling, yet the bullets just continue to pass in front of him.

Revealing: After the TARDIS breaks down the Doctor and Peri can be seen reading the manual, although it is clearly a book of empty pages.

Factual error: One of the characters in this story is called "Lord Ravensworth". Yet the story is set in 1813.and Sir Henry Liddell was not enobled and raised to the Peerage to become Lord Ravensworth until 1821 (eight years later).

Plot hole: Peri goes to a fair bit of trouble to bolt the door on the bath house when rescuing the Doctor. But when the Rani and the Master arrive, they simply open the door. Now this, in itself, isn't a mistake, as the Master has a special gadget for opening locked/bolted doors, yet both The Master and The Rani seem surprised that someone is in the bath house.

Continuity: The amount of dirt on the Doctor's face changes between the Bath House and the exterior filming.

Plot hole: Oscar really does keep a clean restaurant. Even after Shockeye has stabbed him with a knife, the knife is clean, with no unsightly blood to be seen.

Plot hole: Hair is dead, it can't simply change colour (without dye). The second Doctor's hair simply turns orange, instead of growing quickly and the new bits being orange and the ends being black/grey. (Also Patrick Troughton didn't have grey hair during his second year as Doctor, in 1967-68.).

Plot hole: The Bandrils not only know of the Time Lords but are capable of connecting to them, yet the Bandril are barely capable of space travel and can't produce their own food. So, the Bandrils are not very technologically advanced it seems, so why do they have ties with the High Council of the Time Lords? And how does either party benefit from such an association?

Plot hole: Why would H.G. Wells understand the word 'screen' as used to mean computer monitor screen? The modern computer as we know it didn't exist in H.G. Wells' lifetime.

Factual error: It is claimed in "Timelash" that the young H.G. Wells was a teacher. In 1885 (when he is supposed to have encountered the Doctor and Vena), he was apprenticed to a draper in London. He didn't become a teacher until after he had gained a BSc in zoology and geology at university in 1888, three years AFTER the period in which this story is set.

Plot hole: The DJ fires the ultrasonic gun, to demonstrate it to Peri. The glass in the doors breaks. When the Daleks arrive the glass in the doors is unbroken. It then doesn't break the glass in the doors in any of the other times he fires the weapon.

Visible crew/equipment: In the first scene of episode 2 you can see a member of the crew casually walking in the background.