Theory:Doctor Who television discontinuity and plot holes/The Talons of Weng-Chiang


 * When first encountering the Doctor and Leela in the police station, Li H'Sen Chang refers to the Doctor by name without having been told it.
 * Possibly an example of Chang's mental powers given him by Magnus Greel.


 * After encountering the Doctor at the police station: (in Part 2 of the story) Chang informs Greel/Weng-Chiang that although he is able to read people's minds with ease, there is "a" doctor who is different, whose mind he cannot read. In fact describing him as "a doctor" instead of "the Doctor" is probably a mistake picked up when reading the sergeant's mind to learn about the two "strangers" at the police station.


 * There is more than one giant rat in the sewers, so what happens to the rest of them?
 * The Doctor mentions using cyanide to wipe them out. He probably passes the recommendation on to Litefoot or the police before leaving. On the other hand, why does anything have to happen to the rest of the giant rats? Maybe their descendants are still down there?


 * Why does Greel need girls rather than young people in general?
 * He is using the Whitechapel murders as cover, hoping that they will simply be blamed on Jack the Ripper without arousing additional suspicion.


 * If Greel is the first human to travel through time, how would he know of Time Agents?
 * It's never said that the time agents are human.


 * Since the Time Agents use time travel, Greel could certainly have encountered them even though they are from a later time than when he left.


 * Greel could be using the term "Time Agent" quite casually, assuming that his enemies would use the disastrously faulty Zygma apparatus to send their agents after him. At this stage in show history, there is no reason (aside from retconning) to assume that he means any specific organisation of Time Agents.


 * Based on the way he uses the phrase, it does sound that he is referring to a specific agency or classification of people. That being said, the earlier explanation of having met Time Agents from the future still holds as a possibility. Also, since time travel experiments were going on in Greel's time (leading to the Time Cabinet's creation), there was likely already an agency in existence (or being talked about) to monitor/control the use of such time travel.


 * Leela is placed in the distillation chamber near the end. The Doctor uses an axe to destroy the control. Later on, he shoves Greel into the machine, which sparks and smokes and then works like normal.
 * The axe only causes the machine to malfunction, not break down completely. It is still behaving erratically when Greel is shoved into it.


 * When the Doctor smashes the crystal key on the ground, the deactivated Mr. Sin flinches.
 * Residual energy in his systems flickering with life.


 * The Doctor mentions that he shared a fish caught in the Fleet with the Venerable Bede. But Bede spent his entire life in Jarrow, far removed from London. On the other hand, the Doctor could be putting Litefoot on.
 * The Doctor knows something about the life of Bede which is not recorded in the history books. Further, there are a couple of possible trips that Bede in real life made away from his home monastery, as hinted at in letters he sent. A journey to London is not completely out of the bounds of reality.
 * The Doctor caught a fish in the Fleet one day, got in the TARDIS, flew to Jarrow, and shared fish and anachronistic chips with Bede.


 * Litefoot asks the Doctor how does he know the course of the Fleet 'as it has been covered for centuries', although the majority of the river was actually covered in the late 18th and 19th Centuries. In fact, the last section was covered only 20 years before this story is set.
 * Litefoot would not necessarily know exactly how long any given section had been covered, so may believe that much of it (or at least the relevant portion) had indeed been "covered for centuries".


 * When the Doctor and Leela leave the TARDIS, they leave the door partly open. They walk away to the poster of Chiang, then hear the attack on Bullard and run past the TARDIS again. The TARDIS door has magically closed.
 * No magic necessary. It has been well-established that the TARDIS is semi-sentient. It is quite capable of closing its own doors - and opening them, as we later see.


 * When Leela is in Greel's laboratory she blinks twice when both Greel and Chang are looking at her. Shouldn't they realize she is not hypnotized?
 * Maybe they did not notice, as it is normal for any human being to blink, and most people do not notice when someone blinks. Also, where does it say hypnotized people don't blink?


 * Why would the pig part of the Peking Homunculus have caused it to become psychotic? What's psychotic about pigs?
 * Nothing in and of itself, but remove the poor creature's brain and hardwire it into an AI, and it seems plausible that whatever elements of the organic brain retained consciousness will be neither too thrilled nor too sane at the result...


 * Litefoot says that he was brought up in China, then says that his father was on the expedition to China in 1860. However, this would put Litefoot in his early thirties, and he's clearly much older than that.