Diploma engineer Johanna Ditmar's career comes to an abrupt end when her colleague destroys the institute's lab and blames Jo for it. With this messed-up resume, she eventually finds work on an assembly line at a scaffolding company, where one day she collides with the boss, Susanne. The cool, arrogant businesswoman begins to take an interest in Jo, but being suspicious, she digs into Jo's past and learns about the alleged sabotage. Immediately, she shuts herself off again and even accuses Jo of industrial espionage. However, Jo's feelings have grown strong enough that she attempts to free Susanne's walled-up heart.