The Adventures of Tartu

British Captain Terence Stevenson is parachuted into Romania and assumes the identity of Captain Jan Tartu, a member of the Iron Guard. He must blend in using his language skills and chemical engineering knowledge while locating the Nazi poison gas project. The mission is to infiltrate, gather intelligence, and reach Czechoslovakia to strike at the production.

Tartu travels to Czechoslovakia with the goal of stealing the formula for a new Nazi poison gas and sabotaging the plant where it is manufactured. He must navigate dangerous networks and unreliable contacts while staying undercover as a German-aligned operative. The mission hinges on reaching the underground without exposing his true allegiance.

Before he can secure access to the factory, his contact is arrested, forcing a change of plan. He is reassigned as foreman at a munitions factory and given a German uniform, increasing the risk of exposure. He is billeted at the Palacek house with Pavla and her mother, and Maruschuka also resides there, foreshadowing conflicting loyalties.

Pavla shoots a German who had earlier executed her lover. Tartu provides her with an alibi and then reveals his true identity as a secret agent. The revelation confirms they are both working against the Nazis, though their alliance remains fragile.

Tartu asks Pavla to help contact the Czech underground, and she contrives a date with Maruschuka to facilitate the meeting. They speak guardedly but acknowledge that they both resist the Nazi regime in their own ways. The uneasy collaboration begins to take shape.

Pavla is seen attempting sabotage at the plant. She whispers to Tartu to denounce her in order to protect him, and he does so. Pavla is executed as a traitor, a brutal reminder of how quickly loyalties can turn in wartime.

The factory manager rewards Tartu with a transfer to the chemical plant, placing him inside the Nazi-controlled facility. He receives a German uniform and continues his undercover work, improving his access to the critical site.

Maruschuka contacts Dr. Novotny and the resistance leadership, concluding that Tartu might be a spy and must be dealt with. She returns home and tries to stop Vogel from warning others by seducing him, hoping to control the information flow. Vogel, however, intends to report to the Gestapo, setting up a dangerous cat-and-mouse game.

The next day, Tartu brags in a bar about six Czech resistance members about to be arrested, drawing the underground's attention. They abduct him and, after persuasion, convince him they are on the same side and can help him sabotage the plant. They stay up all night drafting a plan and fabricating miniature bombs for placement inside the facility.

Vogel checks Tartu's credentials at the Palacek house and is confirmed as an ally to Maruschuka's suspicions. She believes Vogel and tries to silence Tartu; however, Vogel is killed by Maruschuka, who misreads the situation while trying to protect herself.

Maruschuka hurries to the chemical plant to warn Tartu; he sounds an air raid alarm and runs through the plant, placing the bombs. The Germans quickly realize he is the saboteur, but he completes the task and the plant explodes as he is driven away. The operation achieves its destructive goal despite heavy resistance.

Tartu, Maruschuka, and a pilot steal a German bomber and fly to safety. In a moment of wartime levity, he proposes a simple wedding to seal their bond for what may come after the war.