Top Stasi agent Kleo Straub liquidates a target in a West German nightclub. Soon after, she must face a life-changing betrayal and a heartbreaking loss.

Determined to find her files, Kleo tracks down her former handler and makes her way into Stasi headquarters. Later, she seeks out Thilo in a dance club.

Kleo heads to Mallorca, chased by Sven. She infiltrates a party and uses a toxin to paralyze Wieczorek's wife, leading him to make a deadly confession.

With Min and Uwe on her tail, Kleo bribes a little girl to deliver a poisoned Bundt cake to Mielke's jail cell. After a showdown, Kleo digs up a letter.

Kleo and Sven form a wary alliance. Anne visits Kleo claiming to look for her grandfather. After failing to kill her, Uwe sets up a meeting with Kleo.

Severely wounded in a shooting, Kleo has a revealing flashback. With the ominous red suitcase seemingly in hand, Sven shares a devastating truth.

After Andi is wounded by Kleo, a double agent prevents him from unpacking the conspiracy behind the red suitcase. Sven, Kleo and Min move in on a mole.

Uwe is left cleaning up a mess. Sven unmasks a double agent, while Kleo heads for her family cabin in search of answers.