THE INVISIBLES is a documentary film about the career of Detective Inspector Marianne Atzeroth-Freier by her stepson Matthias Freier. It follows her career through the Hamburg police apparatus of the 1980s and 1990s. At the end of the 1970s, Marianne is 30 years old and a single mother. She was one of Hamburg's first female police officers and is one of the first women ever to be promoted to the Hamburg homicide squad. The headwind in this male-dominated world is strong, she is not taken seriously and is bullied along the way, until she becomes aware of the furrier Lutz R.. Against considerable resistance from her superiors, Marianne investigates in her spare time and makes a significant contribution to solving the case of the "acid barrel murderer".