The season 2 finale of Peacemaker, "Full Nelson," opens a month ago, with Chris Smith and Emilia Harcourt in Big Belly Burger. Things are going well, but the credits start before we get to discover what happened between them on that damn boat.
In the present, Chris has little interest in being visited in prison by his friends, and remains convinced that he's the "angel of death." A.R.G.U.S., meanwhile, explores the Quantum Unfolding Chamber, though many of the doors are locked. One leads to a world that looks like it's made of candy, only for countless tiny creatures to emerge from the grass on the attack. They close the door, trapping Harcourt and Langston Fleury, until they're able to escape from the murderous little blighters.
Harcourt and John Economos are understandably disillusioned with A.R.G.U.S., while Leota Adebayo attempts to convince Vigilante to use all the money he's seized to get Chris a decent lawyer. They bail him out, but Peacemaker immediately leaves town with Eagly.
Back in the QUC, A.R.G.U.S. discovers a black hole that Lex Luthor tells Rick Flag Sr. in a note, "looks promising." Another world is full of zombies, and agents keep dying for reasons which aren't entirely clear (not that Rick seems overly bothered). Still, they finally discover a reality that's exactly what he's been looking for; he calls the planet "Salvation," and the plan is to use it as a metahuman prison.
Sasha Bordeaux requests a meeting with Harcourt and tells her about Rick's plans to send metahuman prisoners to "Salvation" forever.
In a flashback to the boat, we learn that Chris and Harcourt shared a passionate kiss, which freaked her out. She left him hanging, and that's why things have been so awkward between them all season.
Adebayo breaks up with her girlfriend, and Sasha helps Harcourt and Economos find Peacemaker. Vigilante tasers him, and they later convince their friend that people around him only die when he doesn't listen to himself. It's an emotional exchange between Peacemaker and his fellow 11th Street Kids that ends with them convincing him to join them. Chris asks Harcourt if their kiss meant something, to which she finally admits it meant "everything."
One week later, we find the gang—joined by Sasha, Fleury, and Judomaster—setting up their own organisation: Checkmate.
While it seems like a happy ending, Chris is later kidnapped by A.R.G.U.S. and Rick, becoming the first prisoner sent to "Salvation." Make no mistake about it, Flag is a villain, and sends Peacemaker there to punish him for his son's death. It sounds like there are creatures in this mysterious dimension, too, and Chris is currently there all by himself!
In the comics, Checkmate is a governmental intelligence agency established by Amanda Waller. The organisation took its name from the winning move in chess, and its hierarchy was modelled after the pieces in the classic board game. Kings and Queens are the leaders, Bishops oversee missions behind the scenes, Rooks plan the missions, Knights carry out the missions, and Pawns are the support staff.
All episodes of Peacemaker are now streaming on HBO Max.