On the train to Berlin, Emil shares his compartment with a mysterious man in a bowler hat who introduces himself as Herr Grundeis. Emil accepts some chocolate from the man and then falls asleep. When he wakes up, his money has disappeared and so has Herr Grundeis. Emil gets off the train in a different part of Berlin from where he intended. When he spots Grundeis in the crowded station, he follows him, determined to get his money back. Emil dare not call the police because the local policeman in Neustadt has seen him paint the nose of a local monument red (so he feels that he is "a kind of criminal" himself). While Grundeis is eating his lunch in a restaurant, Emil meets a local boy called Gustav and tells him about his mission. Gustav offers to help and assembles a gang of local children who call themselves "the detectives".