Theory:Doctor Who television discontinuity and plot holes/The Stones of Blood


 * How does de Vries control the ravens, and what is their function?
 * She does have access to powerful technology and this power would convince her followers she had powers. Also birds would make good spies.


 * At the start of the story there are three Ogri. One falls off a cliff, but later there are still three. Maybe it survived the fall.


 * If Cessair has escaped from the prison ship, why does she stay on Earth? What's her plan?
 * If we knew that it wouldn't be that much of a secret plan. Why should she leave when she has her liberty? Besides, how could she leave without a ship of her own. It is even conceivable that she is an agent of the Black Guardian or the Shadow, and has been awaiting further orders (not knowing that the Shadow has changed his plan, and is allowing the Doctor to gather up the five segments, thus leaving her expendable).

Cessair may have used her "wand" device to disable it, and prevent it from materialising into real space.
 * Why did the ship get stuck in hyperspace?


 * Why would Cessair be content to live in her tiny cottage when she could still be at de Vries' mansion?


 * The line of empty portrait spaces in de Vries' hall implies that at some point, all four portraits of Cessair (under her various aliases) were hanging next to each other, thus allowing all to see that their subjects are the same person. Why would Cessair ever allow this to happen and run the risk of blowing her cover?
 * The fact that she has moved out of the mansion (as noted above) and started using de Vries and the BIDS as a front suggests that she has been fairly complacent about her secrecy until recently, perhaps having been forewarned (maybe by the Black Guardian) that someone would soon come looking for the Great Seal / Third Segment.