Rachel goes on the warpath, lashing out at Sarah's nearest and dearest. While she tries to keep her loved ones safe, an unexpected visitor threatens to derail Sarah's plans.

Paul digs and finds the ugly truth behind the Castor Boys’ logbooks of names, pushing him into action. Meanwhile, Felix is desperate for info on Sarah’s whereabouts, and presses the still-ailing Rachel for any shred of a lead. In order for Donnie and Alison to take their money-making endeavor to the “next level” she must introduce Jason Kellerman to her unique business plan.

While Sarah and Kira spend some well-needed bonding time at home, secrets are unlocked about Kira’s special gifts that are surprisingly linked to the island’s creature. Meanwhile, Cosima joins Delphine at the mansion for a twisted family dinner, causing a dangerous showdown with the Neolution patriarch.