Molly panics when she discovers she is changing physically – the question is into what, and whether she can reverse what’s happening to her. Also, JD’s ex-wife, Dorothy, shows up suddenly on his doorstep to discuss their daughter.

Molly and JD try to convince Shepherd to broker a peace between humans and hybrids. Meanwhile, Lucy tries to manipulate Charlie’s feelings to put him in a compromising position.

Molly tries to save her son following a raid on the hybrid compound and JD tries to rescue his daughter from Shepherd. Elsewhere, Lucy becomes a bigger threat to humans.

As Molly succumbs to the virus, long forgotten memories surface. Also, Julie is confronted with hard choices and the Hybrids seek revenge.