First, an agent is infiltrated into a German aircraft factory by equipping him with a false identity as a fitter and the fake name "Schultz".
At the same time, the agent group in the capital Berlin places advertisements in which contacts to the industry are sought and good earning opportunities are offered.
As a result, the highly indebted designer Brockau, who is desperate for new sources of income to fund the expensive needs of his pleasure-seeking girlfriend Marion, gets in touch.
Brockau, the inventor of a new type of crude oil carburetor, works in the T-Metallwerke, where the latest German tank models are developed.
Schultz is still able to take off in a new dive bomber model, but is shot down on the Channel coast by a joint action of the Luftwaffe and Kriegsmarine.
The film ends with a roll call at the tank unit's barracks, where the execution of the traitor Brockau is announced.