Keiko returns from Bajor possessed by a dangerous and malicious entity. And O'Brien is stuck fighting the clock to make sure he can get it out of his wife without killing her.
- Adult Fear: The whole episode is this for resident Butt Monkey Miles O'Brien. Especially when Possessed!Keiko is alone with Molly.
- Book Ends: The episode opens with Rom getting the breakfast of choice for the night shift crewman. And ends with him getting the breakfast of choice for the day shift crewman.
- Demonic Possession: If you consider the Wormhole Aliens spirits, anyway.
- Foreshadowing: Jake says that he'd like to see a Pah-Wraith. A year later, he gets possessed by one.
- I Have Your Wife: The Pah-Wraith controlling Keiko.
- Out-Gambitted: The Pah-Wraith, once Rom helps O'Brien figure out what's going on.