Arriving on an underwater base under attack, it’s up to the Twelfth Doctor and Clara to save the frightened crew. But also onboard is an alien spaceship, and the base is being haunted by the most impossible of things.
The Doctor’s deepest beliefs are challenged when he encounters something he cannot explain. Can it really be possible? Can ghosts be real?
NOTES
One of the ghosts was previously a Tivolian. (The God Complex)
The Doctor has previously landed in an underwater base, in which he met with a crew that were tackling a threat that would re-animate the dead crew. (Shadows of the Vashta Nerada)
One of the Doctor’s apology cue cards says: “It was my fault, I should have known you didn’t live in Aberdeen”. The Fourth Doctor dropped Sarah Jane Smith off there rather than in South Croydon. (The Hand of Fear, School Reunion)
When The Doctor goes back on his insistence that the phantoms of the dead aren’t ghosts, he notes that they aren’t flesh avatars, (The Rebel Flesh) Autons, (Spearhead from Space) or “digital copies bouncing around the Nethersphere”. (Dark Water)
Clara tries to “high-five” The Doctor. (Hide)
The ghosts refer toOrion’s sword.
TheOrion Nebula, Orion, Rigel and Betelgeuse are mentioned on a map of constellations.
The Doctor uses cue cards to give apologies.
The Doctor once converted his radio into a clockwork squirrel.
Cass refers to The Doctor doing “the Cabin in the Woods” thing.
Clara refers to people with long necks who have been celebrating New Year for two centuries.
Clara once had an argument with Gandhi.
The Drum has a submarine that can be controlled with submarine manipulator rings.
