After following Grundeis to a hotel and spying on him all night, Emil and the gang follow the thief to a bank, where he tries to exchange the money for smaller bills. One of the boy detectives follows him into the bank and tells the bank teller that the money is stolen. Emil goes in and tries to tell the bank teller his story. He proves that the money is his by describing the holes left by the needle he used to pin the bills to the lining of his jacket. Grundeis tries to run away, but the detectives cling onto him until a police officer arrives, alerted by Emil's cousin Pony Hütchen. Once arrested, Grundeis is found out to be a member of a gang of bank robbers.