Emil is spending his summer vacation with his grandmother in Berlin. But on the train there, he is robbed by the ruthless con artist Max Grundeis and a wild adventure begins! Together with his friends Pony, Gustav, Dienstag, Anh, and Jason, Emil sets off in pursuit and embarks on a fast-paced detective hunt across Berlin.

Chief Inspector Johannes Fischer has retired in the meantime. The last case he investigated together with his former boss Konstanze Satorius has been closed, but Fischer is still convinced that an innocent woman is in custody.