While patrolling Federation space, the USS Shenzhou encounters an object of unknown origin, putting First Officer Michael Burnham to her greatest test yet.

Face to face with Klingon vessels, the USS Shenzhou prepares for the possibility of war if negotiations fail. Amidst the turmoil, Burnham looks back to her Vulcan upbringing for guidance.

Six months into her sentence, Burnham finds herself aboard the U.S.S. Discovery, where she quickly realizes things are not as they seem, including the mysterious Captain Gabriel Lorca.

With tensions and stakes high as Starfleet continues in their efforts to end the war with Klingons, Burnham begins to settle in to her new position aboard the U.S.S. Discovery.

While on a mission, Lorca is captured by the Klingons and unexpectedly finds himself in the company of prisoner of war Starfleet Lieutenant Ash Tyler and notorious criminal Harry Mudd.

The USS Discovery crew is intrigued by new addition, Lt. Ash Tyler. Sarek seeks Burnham's help, rekindling memories from her past. Admiral Cornwell questions Lorca's tactics.

As the crew attempts to let loose at a party, Harry Mudd triggers a time loop that repeatedly destroys the ship and kills the crew in an effort to learn the secret of the spore drive and sell the Discovery to the Klingons.

The U.S.S. Discovery is tasked with a high priority mission to the planet Pahvo and learn the science behind the Klingons' cloaking technology.

Bypassing Starfleet's orders, Lorca uses the USS Discovery crew's ultimate asset, the ship itself, in an effort to end the war with the Klingons once and for all.

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.

Still stranded in the mirror universe, Burnham must try to save the lives of a group of rebels whom she is ordered to destroy by the Terran Empire while maintaining her cover as her counterpart. Meanwhile, a growing terror within Lieutenant Tyler consumes him and threatens the chances of the Discovery returning home.

Burnham heads to the ISS Charon with a special "gift" for the Emperor. With the help of an unexpected source, Stamets gains clarity while trapped inside the mycelial network. Saru asks for L'Rell's help to deal with Tyler.

Lorca plans to move forward with a coup against the Emperor, propelling Burnham to make a quick decision to save not only herself, but the U.S.S. Discovery.

Burnham and the crew are faced with the harsh reality of the war during their absence. In order to move forward, Starfleet must use unconventional tactics and sources to take their next action against the Klingons.

With Empress Georgiou at the helm of the plan to end the Klingon war once and for all, the USS Discovery crew struggles to fathom and tolerate her hostile tactics. Memories of past hardships are rekindled within Burnham.