The U.S.S. 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.

When a new signal appears over Saru's home planet, Burnham, Saru and the crew embark on a perilous mission that puts Saru in danger and raises questions about the Red Angel's intentions. Hugh struggles to come to terms with his new reality.

A fourth signal leads the U.S.S. Discovery to a world where Pike is forced to make a life-changing choice. Burnham and Spock investigate a Section 31 ship gone rogue, leading to a discovery with catastrophic consequences.

After receiving a message from Book, Burnham and Georgiou embark on a rogue mission to find him, leaving Saru to pick up the pieces with Admiral Vance. Meanwhile, Stamets forms an unexpected bond with Adira.

On Saru's last mission as Captain Burnham's Number One, the team ventures to a seemingly abandoned planet to hunt for what might be the greatest treasure in the galaxy.