When a lawyer dies of an overdose, Sabrina and the team track a batch of deadly heroin sweeping through Surrey, leading to a grieving mother challenging the legal and moral limits of the war on drugs.
Katya manipulates Alex and makes him think he’s mistaken when he almost exposes his parents as spies, but her lies lead to a rift in the family. Meanwhile, Victor is warned to keep the O’Connors under control and Alex teams up with an FBI agent.