Tilly and Adira lead a team of Starfleet Academy cadets on a training mission that takes a dangerous turn. Meanwhile, Burnham is pulled into tense negotiations on Ni’Var.

Captain Burnham and the U.S.S. Discovery race to stop Book and Ruon Tarka from launching a rogue plan that could inadvertently endanger the galaxy.

While Captain Burnham leads an away mission to a planet that was once home to the aliens responsible for the DMA, Book and Tarka secretly infiltrate the U.S.S. Discovery.

Trapped inside a mysterious alien portal that defies familiar rules of time, space, and gravity, Captain Burnham must fight Moll – and the environment itself – in order to locate the Progenitors' technology and secure it for the Federation. Meanwhile, Book puts himself in harm's way to help Burnham survive and Rayner leads the U.S.S. Discovery in an epic winner-takes-all battle against Breen forces.