|Air date||August 10, 2018|
When Pidge intercepts a distress signal that the Paladins believe they recognize, the teams ends up on a ruined planet that was ravaged by war.
The Paladins are becoming complacent on their trip to Earth, so Keith and Krolia organize a battle simulation. The simulation is heavily weighted against the Paladins, and they fail. Pidge then picks up a distress signal sent from what appears to be a senior member of the Blade of Marmora. The team heads to a planet and find a devastated set of ruins.
They find a single alien, Macidus, who has several Marmora blades in his presence. Macidus fills the team in on events since their disappearance. With Lotor gone, the Galra Empire fractured, and Haggar's Druids set out on a mission to eliminate the Blade of Marmora. They drew the Blades to the planet and fought a vicious battle, with Macidus being the only survivor.
While the majority of Macidus' story is true, Macidus is revealed to actually be one of Haggar's Druids, and the one who fought Keith years previously. He is using the signal to draw the scattered remnants of the Blades to the planet to kill them. Macidus uses a device to freeze the team, but Cosmo the Cosmic Wolf teleports Keith away in time. They fight throughout the caverns, and find Kolivan alive. Meanwhile, Allura manages to free the other Paladins to join the fight.
Although the Paladins do not help much, Keith manages to defeat Macidus. Kolivan is freed, and Krolia decides to join him in rebuilding the Blades as the Paladins continue on to Earth. Keith hugs his mom and they part ways again.
"Keith, you're out."
— Keith is shown no mercy by Krolia during the battle simulation
"We're not calling him Kosmo."
"Aw, come on, Keith. We gotta call him something."
"I figure when he's ready, he'll tell me his name."
"So Kosmo. Got it."
— The Paladins settle on a name for the Space Wolf, much to Keith's irritation.
- The Bii-Boh-Bi show resembles Seinfeld, including the set - complete with an old style Mac computer near the window - soundtrack and character design elements and behavior, such as the Kramer-style entrance.