While the Klingon fleet approaches Earth, Discovery approaches Qo'noS. Georgiou's Terran tendencies are coming through in her leadership style. Saru and Burnham try to discuss the situation, but Georgiou pulls them apart and picks an argument with Saru. Burnham tries to expose Georgiou, but Georgiou pulls her off the bridge.
Georgiou and Burnham go back and forth. Burnham demands to know the real plan. Georgiou says her knowledge is the only thing giving the Federation a fighting chance to stop the Klingons before they raze Earth.
Georgiou and Burnham pay a visit to L'Rell in the brig. L'Rell is surprised is surprised to see Georgiou. Georgiou wants L'Rell to tell them the best place to drop a landing party. L'Rell refuses. Georgiou goes into the cell with L'Rell and assaults her. Despite being beaten, L'Rell tells Georgiou that the Federation has already lost.
Burnham suggests there's another way. They visit Ash Tyler in his quarters. He's still struggling with Tyler and Voq's memories, but Voq's memories may be able to help them with the Qo'noS assault. He points them where to go, a cave system beneath an Orion embassy. Georgiou wants to bring Cadet Tilly with them on the landing party. Georgiou wants Tilly to carry the mapping probe.
Saru goes to black alert and orders Stamets to jump inside of Qo'noS. The jump puts some stress on the Discovery, but it manages. The landing party beams down. They walk through the Orion encampment. They offer weapons to trade with an Orion. Tilly feigns hunger to pull Burnham aside. Burnham says she has no idea what Georgiou is really up to, but she plans to watch her like a hawk. Tilly says she'll have Burnham's back.
The party visits the Orion "circus," which is essentially a seedy club with dancers. Georgiou pays for a little "me time" with two of the dancers while Tilly guards the drone and Burnham and Tyler continues to look around. They find a gambling game that Voq was good at. Tyler tells Burnham about Voq being an outcast because of his rare albino skin mutation. Tyler gets into the game. He's so at home with the Klingons that it makes Burnham uneasy.
A man convinces Tilly to inhale something he is smoking. Tilly does and passes out.
Tyler returns Burnham but he was unable to get the information they need. Burnham realizes that she never told Tyler about her parents. They were posted at a joint human-Vulcan science outpost. They had planned a vacation, but Burnham begged them to stay home for a few more days so that she could watch a star go supernova. That's when the Klingons attacked. She heard everything. She remembers them laughing afterward and the Klingon laughter here on Qo'noS reminded her of it. She wishes she could hate the Klingon outright, but when she looks around she sees Orions and Klingons just living their lives. Tyler thinks he sees some who may have information on the shrine they're seeking and tries to talk to them.
After Georgiou's "me time" is done, she puts the dancers at gunpoint and demands to know about the shrine.
Tilly comes to as the man is trying to take her probe. The man says the stuff she inhaled is volcanic vapors. The volcanoes are still active. Tilly opens the case and finds a hydro-bomb instead of a probe. She tells Burnham just before Georgiou shows back up, knocks TIlly out, and takes the bomb.
Tilly, Burnham, and Tyler reconvene. If the bomb goes off, Qo'noS will suffer a natural disaster that will make it uninhabitable. They contact Saru, but he can't beam out Georgiou or the bomb. Burnham believes this was Starfleet's plan. She says she needs to talk to Admiral Cornwell.
Burnham makes a transmission with Cornwell and asks if genocide was the plan. Burnham believes Cornwell knows what she's doing is wrong, which is why she kept it secret and sent Georgiou. Burnham tells Cornwell that their principles are all they have. Saru stands up and reminds Cornwell that they are Starfleet. The rest of the bridge crew stands with him. Cornwell agrees to go along.
Burnham finds Georgiou in the shrine. She tells Georgiou that the plan has changed. Georgiou is unimpressed. She offers an alliance to subjugate both Klingon and Federation. Burnham offers Georgiou's freedom in exchange for the detonator. Georgiou refuses. Burnham says Georgiou will have to watch Burnham die again to pull it off. Georgiou agrees to turn over the detonator. Tyler brings L'Rell into the shrine. The bomb is assigned to L'Rell's bio-signs. They encourage her L'Rell to use the bomb as leverage to reform the Empire. Georgiou takes her leave.
In the Orion camp, Tyler tells Burnham that he is going with L'Rell. They have a sad goodbye, hug and kiss. Tyler leaves but gives her the knot he was tying in his quarters earlier. He and L'Rell beam aboard a Mo'kai ship. Burnham beams back to Discovery.
L'Rell makes her case for a united empire in front of the great houses. She installs herself as the new leader of the Empire. The other Klingons laugh. She reveals the detonator and they are silent. She says this is the beginning of the reunification of their race.
With the war over, the Klingons orbiting Earth depart the system. Burnham returns to Earth, where she meets with Amanda Grayson. Burnham reminds her of the time she told her not to forgot her humanity. She says she finally understands. Sarek joins them. He speaks with Burnham. Sarek admits he had a part in the Federation's ploy to destroy Qo'noS. Sarek tells her that her record has been cleared, her mutiny pardoned, and her rank as commander reinstated. The Discovery will also have a new captain.
Burnham is shown giving a speech during a medal ceremony for the crew of Discovery. Tilly has been accepted to Starfleet's command program.
The Discovery is en route to Vulcan to find their new captain. They travel by warp until a non-human interface is found for the spore drive. They receive a distress call on the way. It's from the Enterprise. The ship appears onscreen. They are hailed by Captain Pike.