While in unfamiliar territory, the U.S.S. Discovery crew is forced to get creative in their next efforts to survive opposing and unprecedented forces and return home.

A new signal appears, prompting Stamets' emotional return to the mycelial network and leading Burnham, Pike and Owosekun to a pre-warp planet, where they face a complex ethical dilemma. Tilly's overeagerness lands her in trouble but when the planet - and Discovery's landing party - are threatened, her curiosity may be the one thing that can save them.

When the Discovery crew infiltrates Section 31's headquarters, suspicions arise that the crew may have a traitor in their midst. Burnham tries to help Spock but her efforts don't go as planned.

Reunited with Burnham, Discovery heads to Earth to find out what has happened to the Federation in the last thousand years.

Osyraa attacks Book's home planet and the Discovery travels there to help. Stamets and Adira investigate The Burn.

After capturing the U.S.S. Discovery, Osyraa seeks a meeting with Admiral Vance while Burnham and the crew must overcome unimaginable odds as they attempt to regain command of their ship.

Seeking answers, the U.S.S. Discovery ventures into a subspace rift created by the Dark Matter Anomaly. Meanwhile, Book faces a strange visitor from his past.