Revenge of the Cybermen - S12-E5
Plot hole: The Vogans live on a planet made of gold. They helped develop the gold weapons that defeated the Cybermen. They know the Cybermen are coming and live in a state of paranoia about that eventuality. So why in the world do they attack the Cybermen with useless projectile weapons instead of "glitter guns" or some other gold-based weapon?
Revenge of the Cybermen - S12-E5
Plot hole: Sarah is transmatted down to Voga after being injected with alien poison by a Cybermat. According to the Doctor, the transmat will recognise Sarah's human molecules and separate and reject the (non-human) poison molecules. As clothing fabrics tend to made of non-human molecules, how come Sarah and Harry didn't arrive on Voga stark naked?
Plot hole: It is never explained why so much of the story takes place in England. All of the equipment for Sutekh's rocket comes from his tomb and could just as easily - probably more easily - have been set up right there in Egypt. And at the end, instead of just walking out of his tomb, he takes the spatial corridor to England just so he can get caught in the Doctor's trap.
Plot hole: Why is the warning about Sutekh broadcast in English? (It clearly is as the Doctor identifies three E's in the transcript).
Plot hole: At the very end, the TARDIS materializes in Antarctica and Sarah comments that they've returned. But the TARDIS was never there - the Doctor and Sarah went to Antarctica by helicopter.
Suggested correction: But THEY were there.
Plot hole: Palmerdale and the others hear someone on the stairs. Skinsale opens the door and, despite Reuben being right in front of him, looks downstairs and calls out to the Doctor before turning and suddenly spotting the lumbering keeper.
Plot hole: The damage caused by the shuttle crashing into the Bi-Al Foundation is seen BEFORE it actually happens.
Plot hole: The Doctor's clone is free of the virus - so why is Lowe's clone infected? Perhaps they infected him after cloning, in which case, why is Lowe cloned at all?
Plot hole: After the Doctor and Leela's clones fade, the camera pans to show Leela's knife. But since the knife was created in the cloning process, it should have faded out with Leela, the Doctor and their other personal items.
Plot hole: Why doesn't Lowe simply shoot Leela the second her back is turned? Moreover, why does he take them to get medical help? It's made clear that the virus has everything it needs on Titan.
Plot hole: The Nucleus of the Swarm is referred to on numerous occasions as being a virus. A virus is the simplest form of life yet recognised and is made up of bundles of DNA wrapped in a coating of proteins. They reproduce by attaching themselves to other lifeforms and releasing their genes into an unsuspecting host cell. Viruses do NOT lay eggs. Nor do they resemble prawns.(It would be more accurate to describe the Nucleus of the Swarm as a protozoan. These are simple animal lifeforms radically more advanced than viruses, around a fifth of which are parasitic although not all cause disease).
Plot hole: In the middle of chasing the Doctor, Stor abandons the idea of controlling Gallifrey in favour of destroying it for no readily apparent reason.
Plot hole: Leela's decision to stay with Andred is very sudden. They barely speak during the serial.
Plot hole: After Romana and the Doctor hide in the relic room, the Captain enters, then bends down to inspect the door that conceals the Shrivenzale. Unfortunately, the actor turns to his right when he does so, which make it rather odd that he doesn't see the white-clad Time Lady standing right in front of him.
Plot hole: Mr. Fibuli reports that the aircar the Doctor tried to steal is immobilized. Yet somehow, K-9 is able to activate it.
Suggested correction: Mr. Fibuli was wrong.
The Armageddon Factor - S16-E6
Plot hole: In episode four, Merak expounds on how only the Doctor and Romana can get into the TARDIS, despite the fact that he shouldn't even know what the TARDIS is. His insight continues in episode six, where he talks knowledgeably of the sixth segment of the Key to Time, despite having been told nothing about it.
Destiny of the Daleks - S17-E1
Plot hole: The Daleks spend a lot of time and effort mining down to where Davros is, despite the fact that there is a window on that level and Davros is on the ground floor.
Plot hole: In episode 4, watch what Romana does to Professor Kerensky's time machine in order to make it work. It is surprising that the time machine works at all, considering she is supposed to be in Paris at the time. Romana wires up the time machine to a British (i.e. 3-pin 240 volts) electric plug instead of a "continental" 3-pin 110 volt plug.
Plot hole: The Atlantic Ocean didn't exist in Early Devonian times (c.400 million years ago), so Scaroth's ship could not have been where the Doctor claimed. The Atlantic was formed when Europe and Africa separated from North America around 160 million years ago and is still growing. What is now the sea-bed was once covered up by several miles of Continental Shelf. The Early Devonian landscape would have been far from barren as plantlife was well established by then. So, either the Doctor's theory that Scaroth's exploding ship caused the creation of life on Earth is wrong, or it was much earlier than he said.
