Discovery ventures to the Verubin Nebula, where Burnham, Saru, and Culber make a shocking realization about the origin of the Burn. The rest of the crew faces an unexpected threat.

As the Emerald Chain tightens its grip and the mystery of the Burn is finally solved, Burnham and the crew have one last chance to save themselves - and the Federation.

After months spent reconnecting the Federation with distant worlds, Captain Michael Burnham and the crew of the U.S.S. Discovery are sent to assist a damaged space station – a seemingly routine mission that reveals the existence of a terrifying new threat.