While en route to Earth, Keith and Krolia encourage the team to run a battle simulation in order to maintain a routine. Later, Pidge picks up a coded distress signal from what is likely a senior Blade of Marmora member. The team follows it to a planet with ruins of an ancient civilization and find Macidus, a solitary alien who has a collection of Marmora blades. Macidus explains that following Voltron and Lotor's disappearance, the Galra Empire was destabilized and Haggar's Druids set out to exterminate the Blade of Marmora. A big battle took place on Macidus's planet, and he thinks he is the last survivor...
...Except that was a lie, and Macidus is actually one of Haggar's Druids (specifically the one that fought Keith all the way back in season one), using the signal to lure Marmoran agents to the planet. Macidus freezes the team save Keith, who is teleported away just in time by the wolf. Keith engages Macidus in battle, the two of them teleporting through the caves throughout, and Keith eventually finds the captive Kolivan. Meanwhile, Allura's magic frees the rest of the team, although they are ultimately ineffective against Macidus. Keith disposes of Macidus and the team frees Kolivan. Krolia decides to join Kolivan in helping rebuild and reunite the Blade of Marmora, and bids goodbye to Keith and the team.
Tropes:
- Big "NO!": Parodied on the Bih-Bo-Bii sitcom when one of them collapses on the floor; the other cradles them in their arms and cries "Bii!" at the sky.
- Krolia does this when Macidus drops an item that freezes everyone in its range but Keith, who Kosmo teleports away.
- But Now I Must Go: Krolia apologizes to Keith when she has to tell him she needs to stay behind and help Kolivan try and contact the other surviving Marmora members, despite promising that she would never leave him again.
- Character Development: Keith understanding the reason why Krolia has to leave and help Kolivan recuperate, even giving her back her knife and reassuring her that they would meet again before the two hug and part ways.
- Creepy Souvenir: Macidus keeps the blades of the Marmoran agents he has killed planted in a wall.
- Curbstomp Battle: Macidus spends most of his fight with Keith with the upper hand and swiftly demolishes Lance, Allura, Pidge and Hunk within seconds when they attempt to join.
- I Ate WHAT?!: Lance's disgusted reaction after Hunk informs him that he just ate something made of fungus paste from beetle dung.
- Jump Scare: As Keith turns around figuring that Macidus didn't spot them, the latter teleports on top of the bridge and stabs his sword down in his direction, causing Keith to scream.
- Killed Offscreen: Played straight with many of the Blades, who died in battle against Druids (or, depending on how much of the exposition is true, Macidus himself); subverted with Kolivan, whom Macidus attests to be dead but is actually barely hanging on to life. Keith rescues him.
- Last Stand: Many of the Blades were pulled from assignment and regrouped on the planet when the Druids began to enact The Purge, with Kolivan deciding they needed to make a stand.
- Malevolent Masked Men: Macidus' character, he doesn't reveal his face at all until Keith slices it in half.
- Not So Stoic: Krolia is much more emotionally open throughout the episode, especially when she finds Macidus' collection of Blade weapons.
- Parental Title Characterization: After finding out that she needs to leave again to help regroup the Blades, Keith gives his knife back to her, saying they'll meet again and finally calls Krolia "mom".
- Pre-Explosion Glow: How Macidus is shown to die.
- The Purge: Following Haggar's and Voltron's disappearances, the Druids set out to destroy every Blade operative. Krolia notes after examining Macidus' collection of blades that while he dealt a critical blow to the Blade of Marmora that some still remain.
- Put on a Bus: After Krolia reunites with Kolivan and decides to help him reunite the Blade of Marmora, she bids goodbye to Keith and the rest of the paladins. Having come to terms with his abandonment issues, Keith is much more calmer about the parting and assures Krolia they'll see each other again.
- Sole Survivor: Assuming Macidus wasn’t also lying about the battle’s outcome itself, he is the last remaining Druid, or at the very least the only one to have survived the battle with the Blades.
- Teleport Spam: Both Macidus and Keith (with Kosmo) constantly teleport through their battle.
- Throwing Your Sword Always Works: Keith does this in order to kill Macidus.
- Undying Loyalty: Macidus is shown to be fanatically loyal to Haggar. During his fight with Keith, he rants about how Voltron caused Haggar to “forsake” him. It really says something when you realize that he’s been living as a hermit on an abandoned planet out of pure loyalty to Haggar.
- Unwilling Suspension: Kolivan when Keith finds him. Despite Krolia figuring out that her leader was still alive, his current condition seems close to the verge of death.
- Unwinnable Training Simulation: Krolia's new simulation program is designed to be unbeatable, and she wants to see how long the team survives. Since everyone just rolled out of bed when they first try it, they don't last very long.
- Verbal Backspace:Romelle: This place is disgusting.
Macidus: I have called this place home for two [years].
Romelle: Oh!... 'Disgusting' is Altean for 'lovely.' You don't speak Altean, do you? - Wounded Gazelle Gambit: Macidus pretends to be senior Marmoran agents sending a distress signal and goes to kill the agents who do answer it.
