The episode opens with what appears to be an electrical storm. However, as the camera pulls out, it is eventually revealed to be Burnham's new uniform being synthesized. She's temporarily assigned to science division with no rank.
Tilly walks in on Burnham looking at herself in the uniform in a mirror. Tilly brings her a package. When Burnham attempts to open it a voice informs her that it is the last will and testament of Captain Georgiou. Instead of opening it, Burnham shoves it to the side and heads for the bridge.
Burnham runs into Saru in the turbolift. They discuss Burnham being added to the crew of the Discovery, with Saru certain that Burnham's name was on the manifest of the prisoner transport ship that left already. Burnham notices the Kelpian's threat ganglia is exposed and assures him that she is not a threat. He is not convinced.
They find the bridge on alert and in combat with the Klingons. The Klingons would have destroyed them if not for this being a simulation. Lorca explains that the Discovery is the only ship in Starfleet with the experimental spore drive engine. That means they can go anywhere, but when they do they will be alone. They need to be ready to hold their own.
Lorca walks and talks with Burnham. Lorca says they need to survive and that he has a better use for Burnham, a xeno-anthropologist, than working on Stamets' project. Lorca shows Burham his collection of some of the deadliest weapons in the galaxy. He then shows her his latest addition, the monster from the USS Glenn. The creature has a natural aversion to light. Considering what the monster did to a dozen Klingons on the Glenn, Lorca sees the monster as an opportunity and he wants Burnham to weaponize it.
Voq and L'Rell are still aboard T'Kuvma's ship. For six months, they have been searching the debris field from the Battle at the Binary Stars for a Bird of Prey engine to restart their ship.
They have found none. L'rell thinks they should take the engine from the ruins of the Shenzhou. Voq does not want to sully T'Kuvma's ship with a piece of the ship that killed him. L'rell has a conversation with him about the uselessness of purity and tells him to build a bridge for his people.
Landry joins Burnham in Lorca's armory. Landry is eager to find a way to weaponize the creature, but Burnham points out that the creature resembles a microscopic organism and likely is not actually aggressive. Landry doesn't care and is determined to find a way to utilize it for Lorca's war effort.
Lorca gets a call from an admiral with a distress call from a dilithium crystal mining colony on Corvan 2 under attack by the Klingons. The Discovery is the only ship nearby. Lorca promises than can get there, but when he talks to Stamets about it they argue. Stamets can't figure out how to fully load what they brought back from the Glenn. He agrees to make some adjustments to try to make the long jump happen.
Kol joins L'rell and Voq on T'Kuvma's ship. He apologizes for his insults before the beginning of the war. Kol wants T'Kuvma's shi with its cloaking technology back in the fight. Voq explains their situation but offers the ship and the aid of House T'Kuvma to Kol.
The Discovery is ready, or as ready as it can be, to make the jump to Corvan 2 and Lorca puts the ship on black alert. The creature from the Glenn seems agitated as the spore drive begins to spin on.
The Discovery makes the jump but ends up over a star instead of Corvan 2. They manage to break free.
Burnham shows Landry that the creature reacted before the ship made a jump and that its likely connected to the spore drive. Landry does not care because that information doesn't help Lorca.
In sickbay, Stamets and Lorca argue about trying to make the scientific process work in a time of war. Stamets leaves, and Lorca plays the audio from the transmission from Corvan 2 for the entire ship to hear.
Landry pulls a gun off of Lorca's wall. She fills the creature's with a sedative and releases it, but the creature goes berserk. It gets ahold of Landry and mauls her. Burnham turns the lights on the creature retreats to its holding pen. Burnham brings Landry to sickbay, but she's dead. Lorca doesn't want her death to be in vain.
Burnham summons Saru to Lorca's room. She feigns an apology to draw him closer to the creature and notices that his threat ganglia do no react. That makes her sure that the creature is not a predator. Saru is annoyed and says Burnham will fit right in with Lorca.
Tilly brings a canister of the spores to Burnham. Burnham opens the creature's containment pen and releases the spores. The creature reacts in a friendly manner.
Burnham show footage from the Glenn to Stamets, that the lab was holding something inside. Burnham believes the tardigrade creature found its way onto the Glenn and that it was the means the Glenn used to control the spores.
Stamets and Burnham bring the creature down to the mushroom forest. The creature has a symbiotic relationship that allows it and the spores to communicate, which could make the creature useful as a navigator.
The Discovery goes son black alert. The tardigrade and the Glenn tech to make the jump and find he has all of the coordinates of known star systems inside its head.
They jump to Corvan 2. The ship finds itself in the midst of a battle with Klingon Birds of Prey. The Discovery drops several large explosives to destroy the Birds of Prey and then teleports away. The miners do not even know who saved them.
Voq is left on board the Shenzhou to die.
Burnham visits the tardigrade in the containment pen and brings him another canister of the spores, however, the creature no longer trusts her.
Tilly finds Burnham in their room. She encourages Burnham to open Georgiou's last will and testament. Tilly leaves to give Burnham privacy. She accepts the Georgiou's last will and testament. A hologram of Georgiou plays. She assumes Burnham has her own command now. She's left her her most treasured possession in order to encourage her to continue to explore the mysteries of the universe. Georgiou says she is as proud of Burnham as if she were her own daughter. Burnham opens the package to find the telescope from Georgiou's office on the Shenzhou.