Theory:Doctor Who television discontinuity and plot holes/The Unicorn and the Wasp


 * Donna investigates a room in the manor house - which has been locked for forty years. However, in the room, there is a teddy bear. Teddy bears were introduced (and became popular) at the turn of the 20th century.
 * It being actually locked for forty years probably wasn't literal, as the room would have to be opened, etc. It is also possible that the room has just become a storage space. It could also be a misplaced hint that Lady Eddison had a child in the room, since a teddy bear is usually a child's toy.


 * The "thieves in the night" at the church seemed to be committing their crimes in broad daylight.
 * Rev. Golightly is making a Biblical allusion: see 1 Thessalonians 5:2.


 * Agatha mentions her extensive study of poison, claiming that cyanide poisoning is invariably fatal. In reality it can be countered by several methods, including the administration of nitres, hydroxocobalamin or certain chelants. It is surprising that she sniffed the drink, as hydrogen cyanide is one of many poisons that can readily be absorbed via inhalation. Ms. Christie gained her knowledge of poisons by working in a V.A.D. dispensary during WWI, so she would have known this in 1926. (See The Agatha Christie Companion by Sanders and Lovallo. ISBN 0425118452)


 * How could the Vespiform hold the lead piping?
 * With one of its arm/legs or a mandible.


 * Even though it turns out that Reverend Golightly tried to poison the Doctor, why did the Butler still give him an odd look?
 * A reference to the good old plot device of "the Butler did it". Furthermore, the Doctor's behaviour is frequently odd enough to draw suspicious glances.


 * Agatha disappeared in December which is in the Winter and the weather is that of a summer or spring.
 * It can be sunny in Winter in England. Plus, it only remains sunny for a while; when Roger dies it is extremely stormy.


 * The Doctor seems to have gotten over Jenny's death pretty quickly.
 * It is likely that some time has passed since her death, and the episode does not mention anything about the previous episode.


 * While the Doctor tells Donna about the Curbishleys at the party, he says Roger will one day become a Lord, but Roger is killed by the Vespiform the very same day.
 * He isn't predicting the future, he's explaining the peerage system. It's quite clear he didn't know what was about to unfold.