A space crew preparing for the first human flight to Mars is faced with a life-altering decision… and its consequences.

The darkest days of the void arrive as Sabrina struggles with grief and regret. Can she summon the strength to overcome an endless cycle of destruction?

Jaha employs a terrifying new method to convince Abby to join his cause, Kane is on a mission, and Bellamy is hit with a hard truth. Meanwhile, Monty finds himself…

Alie forces Raven’s dark side to come out, and Jasper’s anger continues to grow. Meanwhile, Octavia wrestles with her place in the world, and Monty is forced to make a…

When Mulder and Scully try to discover what unseen force may have driven a scientist to commit suicide, they turn up a laboratory where extreme genetic experimentation has bred subjects…