Poke and Pena, two private investigators in debt, see an advertisement in the newspaper about Dr. Peltonen's disappearance and the promised reward for finding him. The boys retreat to investigate the case in a house they have rented in the countryside, which happens to be next door to the criminal gang that kidnapped the doctor. The gang's boss, 'Synkkä' (Gloomy), and his sister, 'Kaunotar' (Beauty), try to distract the boys by hiring them to guard their villa.