- Action Girl: Elaine Sharkey.
- Conservation of Ninjutsu: Early in the story, a single Elder Thing can easily kill a human. Near the end, the heroes are able to hold a large group of them at bay.
- Corrupt Corporate Executive: LaHune.
- Cosmic Horror Story.
- Cthulhu Mythos.
- Hive Mind.
- Precursors: The Elder Things.