Theory:Doctor Who television discontinuity and plot holes/Mummy on the Orient Express


 * How did Maise and Clara come by passenger manifests from other ships in the sarcophagus room?
 * A passenger manifest might be in a storage room for any number of logistical reasons. It makes sense, for example, if the room contains luggage or other items belonging to one or more of the passengers.
 * The manifests were of previous attempts to figure out the mummy. Many researchers have been killed, and it makes sense for Gus to keep their names to review the order and check it against research results.


 * Why did Gus try to stop Clara and the Doctor from discussing previous attempts to study the mummy, when past data from those attempts may have helped the current one?
 * Gus may have thought the conversation was more concerned with figuring out why they were brought there (which may have in turn lead them to find out more information about him and his motives).


 * Why were Moorhouse (the 3rd victim), Maisie and Ms. Pitt on the train at all? They had no expertise that would've been useful for Gus' test.
 * Gus was willing to sacrifice as many people as necessary to learn the Mummy's secret. And since he doesn't want to have some of the researchers die before they know what's happening, it makes sense for him to have brought "extras" to die so everyone would start researching. Of course, the fact that the "extras" die first means he already knew something about the death order, which means previous research groups were at least partially successful.