Will makes a sacrifice to protect his family. Katie races to save refugees outside the walls. Snyder struggles to control a Colony amidst the chaos of war. Bram and Gracie make a big decision.
Grace forges a dangerous alliance with Claire’s brother, Alonzo (Ashley Thomas). Also, Harris and Darius must work together to face down Bennett’s forces.
The secret of the asteroid becomes public following a nuclear incident, setting the world on a dangerous course. Also, Darius, Grace, Liam and Harris must adapt to new roles in an ever-shifting landscape of fear and civil unrest.
Darius and Grace must forge an emotional détente in order to get international cooperation. Also, Liam meets a new scientist with a mysterious past.
Grace embarks on a dangerous mission, and Liam and Darius' relationship is tested.
