In Kaliningrad, Polish spy Ewa goes undercover to gather critical information on a prominent Russian nuclear engineer.

Ewa helps a key target escape, while Lange works to keep his agents safe. In Riga, Tamara searches for answers.

Amid threats of a dirty bomb attack, Tamara closes in on Ewa’s family, Skiner vows to protect Kaj in Krynki, and Ewa uncovers intel about Skopincev.

Despite being sidelined, Ewa persists with her mission, uncovering crucial intel about Russia's dirty bomb and a plot to stoke the flames of war.