Spencer joins S20 to take down Zayef for good. But when intel leads them back to the Demachi's, S20 finds itself embroiled in a feud that may expedite Zayef's plans and place military-grade weapons in the hands of terrorists across Europe.

With Chetri in the wind and Carolyn on their tail, Novin, Wyatt and Coltrane are forced to weigh loyalty against duty and self-preservation; still blacklisted and left with scant resources, S20 seeks the help of Russian allies to combat Russian foes.