While pursuing a Marquis vessel, Odo and Kira wind up trapped on a small moon in the Badlands. Kira's foot is caught in some kind of growing, expanding crystal that will eventually overtake her entire body, and Odo isn't able to remove it or transport her back to the runabout, being forced to helplessly watch as the situation grows more and more desperate. Meanwhile, back on DS9, Nog seeks a recommendation from Sisko for his application to Starfleet Academy.
- Anguished Declaration of Love: Odo to Kira. Except it turns out that it isn't really Kira.
- Call Back: O'Brien's kayaking hobby, first mentioned in "Transfigurations" is mentioned by Odo.
- Determinator: Nog is bound and determined to join Starfleet, despite everyone thinking it's a joke or a prank. He spends the whole episode pursuing Sisko's recommendation for his application, and gets it when he proves he's serious.
- Foreshadowing: Odo is unable to get a good reading on the crystal that's slowly encasing Kira, and notes that it's almost like the crystal is mutating continuously to keep them from finding out what it is. That is exactly the case.
- Hidden Depths: While Rom has been fixing the odd broken replicator in the bar, this is the first time that it's mentioned he's actually a mechanical genius who could have been chief engineer of a starship had he been given the opportunity. Season 4 would clearly demonstrate this instead of it just being an Informed Ability.
- I Am Not My Father: Why Nog is so dead-set on joining Starfleet. He doesn't want to waste his engineering skills like his father.
- I Can't Believe A Girl Like You Would Notice Me: What the female Changeling tries to convince Odo of in regards to Kira. He believes it.
- Mr Seahorse: Sisko and Bashir discuss an upcoming baby shower for one Ensign Vilix'pran, who is about to become a daddy.
- Name One:
Odo: After all, we've been in worse situations than this one and come out all right.
Kira: Name three.
Kira: I can't think of any either.
- Something They Would Never Say
- So Proud of You: Rom defies Quark and proudly lets Nog enlist in Starfleet.
- Spotting the Thread: Aside from his observations of Kira in the past, Odo's first clue that all is not right is that the phaser marks from the supposed Maquis are directly behind Kira, meaning she should have been hit.
- Tearjerker: Odo confessing to Kira when he thinks that she's about to die, and she's desperately ordering at him to leave before he gets killed too.
- That's an Order: Kira to Odo, when she's trying to get him to leave her behind so that he doesn't risk being killed by the seismic tremors causing the cave to collapse.
- Traveling at the Speed of Plot: Odo attempts to transmit an emergency message from the Badlands, and the computer informs him that they should receive the message in approximately two days, because the plot depends on Odo and Kira being stuck where they are with no hope of outside help.
- The Trickster: The Maquis vessel was the female Changeling all along. She lured Odo and Kira out to the Badlands, then kidnapped Kira and impersonated her in an attempt to get Odo to come join the Dominion.