The USS Credence is attacked by a team led by a Qowat Milat nun. In stealing the dilithium shipment, she kills the ship's commander.

At Starfleet HQ, Burnham, Vance, Rillak, and T'Rina debrief the attack. The killer is identified as a Ni'Var citizen and Qowat Milat nun known as J'Vani. They were able to track the dilithium and have her coordinates.

A contingent of Qowat Milat joins them, led by Gabby Burnham. She believes J'Vani is acting as a qalankhkan and the issue is internal. She asks that Starfleet give them the coordinates so they can track her themselves.

Rillak suggests they join forces and offers the services of Discovery and Burnham to assist Gabby Burnham and her sisters.

Rillak approaches Burnham alone afterward and reminds her that she is in charge although the joint mission is necessary to assure that Ni'Var and the Qowat Milat feel respected.

Burnham promises that J'Vani will be brought to justice.

Tilly sits down with Saru and explains she's trying new things. She asks to water some of his plants. He mentions that he has a call to Kaminar to take soon but that she's welcome to water his plants.

Stamets examines the anomaly data. Burnham comes in to ask Book to borrow his ship. She checks in with Stamets who has named the anomaly "DMA" for "Dark Matter Anomaly". He thinks it's a primordial wormhole except that it has no tachyons.

Book wants to come with Stamets to Ni'Var but Stamets is worried about discussing the destruction of Kwejian in front of Book. Book assures him that he can handle it.

Gray and Adira watch the construction of Gray's Synth body.

Guardian Xi arrives to perform Gray's incorporation.

Burnham discusses the mission with Saru and he suggests she take Tilly with her.

Tilly chats with Gabby's Qowat Milat sister while Burnham debriefs on J'Vani with her mother. As they approach the coordinates, Burnham and Tilly are forbidden to take phasers with them. They are armed with swords instead.

As they land, Tilly detects the tracker. Suddenly, mercenaries transport on board. A fight ensures. Gabby's sister nun is killed.

J'Vani appears and warns them to leave.

Gray's unjoining from Adira is a success but Guardian Xi does not sense Gray in the synthetic body. He advises that they be patient. It may take some time.

Michael, Gabby, and Tilly beam into the subterranean cavity on the moon and find ruins. Tilly finds J'Vani's cloak draped on a grave container. Michael lifts it and finds a completely alien species in the container.

There's a rumble and Gabby realizes the moon is a ship and it's being fueled by the dilithium J'Vani stole.

Stamets addresses the Ni'Var scientists. They begin a meditation. T'Rina offers Book a comfort for his grief. She feels he must free himself from guilt.

Tilly examines the reaction system for the moon-ship. Michael finds a record of the moon-ship's departure. Gabby realizes the bodies they thought were corpses are actually in cryo-stasis. Michael reveals Tilly has to be bait now.

Adira is upset by the waiting. Culber counsels them. Saru sits down with Culber and commends his efforts.

Adira goes back to sickbay and talks to Gray's body, hoping to guide him to his body.

On the moon-ship, J'Vani takes the bait. She and Gabby fight. J'Vani gains the upper hand. Michael begins a parlay while Tilly works to repair the ship's engine.

J'Vani identifies the sleeping species as Aronians, the last of their kind. She was telepathically drawn to the ship when it was hit by grave robbers looking to taking the latinum in the Aronians' biomatter.

Michael offers to help wake the Aronians in order to fulfil J'Vani's oath.

On Ni'Var, the scientists find no way to prove Stamets's theory. T'Rina offers to mindmeld with Book to access his memory of Kwejian's destruction.

T'Rina gleans the information she needs but Book uses the opportunity to see Leto one last time, to confirm that he knew how much he was loved. Upon returning, T'Rina confirms no evidence of tachyons.

On the moon-ship, Michael fixes the system and awakens the Aronians. J'Vani recognizes her journey is complete. Gabby takes her into custody. Together, they mourn their fallen sister. Michael calls them to see the Aronians migrate from their ship to their new planet.

Tilly talks with Gabby about the Qowat Milat philosophies.

Michael and Gabby discuss the mission. Upon return to Starfleet, J'Vani is remanded to T'Rina and extradited to Ni'Var. This doesn't sit well with Michael but Vance gives her an analogy to chew on.

Tilly visits Saru to help with his plants.

Gray's vitals start to come online. He wakes up with Adira holding his hand. Culber comes in and Guardian Xi checks in on him.

Michael returns to her quarters where Book has a holo of the Kwejian forest playing. He's found some peace.