The Doctor, Amy, Rory and new travelling companion Kevin — a cybernetic dinosaur — arrive on a familiar-looking space station. They find a scientific crew under attack from a giant, Cthulhloid space squid! With the security robot destroyed, it's up to the Doctor and his friends to save the day. Who will sacrifice themselves to save the many?
to be added
- Eleventh Doctor
- Amy Pond
- Rory Williams
- Commander Katic
- Big Dawg
- High Priest
- Ensign Quinn
- The Doctor claims Nebula Base makes the best granberry smoothies in the cosmos. Rory tries to correct the Doctor, asking if he isn't referring to cranberry smoothies, but the Doctor says that he is indeed talking about granberry, and that is tastes like mince.
- The Doctor took Amy, Rory and Kevin to Japan, where the people mistakenly thought that Kevin was going to eat Tokyo.
- The star cruiser Heaven's Tentacle docks at bay 17.
- When listing various religion's nemeses, the Doctor mentions the Antichrist, the Beast, and Sutekh the Destroyer. He almost adds Beep the Meep to the list but changes his mind.
- The Cthulhoid space squid's name is a reference to H.P. Lovecraft's fictional monster, Cthulhu, which is squid-like in appearance.
- The staff at the space station bear the names "Fillion", "Katic", "Quinn", "Huertas" and "Dever", a reference to Nathan Fillion, Stana Katic, Molly Quinn, Jon Huertas, and Seamus Dever, the cast of the American television series Castle. Artwork of the characters closely resemble those of the actors they are named after.
- Rory mentions protecting Amy for two thousand years. (TV: The Big Bang)
- When freeing Amy from the squid's mind control, the Doctor reminds her of how she beat the Dream Lord's game. (TV: Amy's Choice)
- While regaining her own thoughts, Amy recalls fish fingers and custard and her "raggedy Doctor". (TV: The Eleventh Hour)