Daisy: Does that line work in the future? Deke: Guess not.
Downer Ending: The episode ends on a decidedly low note. Jemma has been Made a Slave by Kasius, Coulson, Mack and Yo-Yo are being forced to work for Grill to avoid capture or death and it turns out Daisy may have destroyed the Earth. The only bright spot is that May is free and has avoided suspicion, leaving her and Daisy free to save the others.
The Dragon: Sinara, the silent female Kree who uses two telekinetic spheres as weapons, acts as Kasius's executioner.
Earth-Shattering Kaboom: According to Deke, Daisy quaked the entire Earth apart, leaving barely a quarter of it intact in the present. It's hard to say if he's completely right about that, since he's working off of scattered historical records.
Foreshadowing: Grill is seen arguing with a man about docking him pay for insubordination. That very man gets "marked" in the next purge and he decides to come at Grill with a vengeance. Unfortunately, Grill tries to use Coulson, Mack, and Elena as bait, only to be saved by May and Tess.
Future Imperfect: Humanity's grasp of their own past is so screwed up, Tess thinks that Sharknadoes were a real type of natural disaster. Justified since the Kree destroyed all historical records when they took over the Lighthouse, leaving humans with only the memories and oral history.
Getting Crap Past the Radar: Mack prompts Elena to steal a Kree tablet with "Ready...and go" countdown, but she returns before he finishes speaking. She grinningly tells Mack that his "go face" looks funny in slow motion.
Internal Retcon: The Kree erased all historical records to keep humanity from understanding what happened to their world, and killed all those that had any knowledge of it.
Leitmotif: Sinara gets an incredibly ominous bass-heavy one that accompanies her everywhere and gets more intense when she starts levitating her telekinetic ball-weapons.
Lotus-Eater Machine: Deke is running a Framework simulation that lets people experience an approximation of Earth. Daisy lampshades it as an opium den, and Deke admits that the Kree let him get away with it because it keeps the people docile.
Narcissist: Kasius is obsessed with beauty, both in his slaves and himself. He kills Reese, the slave Jemma saved, because he had a facial cut marring his features, and keeps Jemma as a replacement due to her beauty.
Jemma blows her cover when she instinctively cauterizes the stab wound of one of the overseer's slaves, which is medical knowledge no human in the Lighthouse should possess. Jemma tries to write it off as something her mother taught her, but her lack of a Marker and pristine condition despite claiming to have come from sewage processing make Kasius suspicious.
The others warn Daisy and Yo-Yo about this, pointing out that the Kree and the other humans don't know about their abilities. Given that the Kree created the Inhumans, using their powers too openly would make them both targets.
Shameful Strip: Jemma is told to undress to clean herself before seeing Kasius. It's implied that Sinara watches Jemma as she is about to do this. Although, it's obviously just to make sure she doesn't try to escape.
The Sociopath: Kasius is a slaveholder who thinks it's acceptable to dispose of a slave because of a minor scar. This slave in particular was supposedly his "most precious" and he treats the event like disposing of a decoration; dispassionate, unaffected and completely lacking in empathy for either the slave's fear or Simmons' distress.
Spotting the Thread: Between Deke last episode and Kasius here, it appears the team's lack of markers or scars is going to be an obvious tip-off that they're not actually from the ship.
Temporal Paradox: Deke seems oblivious to the obvious flaw in his blaming Daisy. She has travelled to the future, and if she never goes back she cannot possibly be the one who destroyed Earth. note It's later explained by way of the temporal mechanics in this setting; time is not singular, so it was Alternate!Daisy that did it.
Wham Line: Daisy is told how Deke believes Earth was destroyed:
Deke: You see, I'm the one person who's pieced the history together — who has an idea of what happened. You wanna know what kind of force can tear a planet apart? It was you.