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.