About the book: 2021 / The town of Bayport is once again restless. This time, the Hardy brothers will have to investigate three cases at once: a bank robbery, brawls in the Slums on the ocean and... the kidnapping of the Hardy brothers' friends, Chet and Biff. It seems that the investigation of three cases at once has reached a dead end, because there is enough evidence, but it is almost impossible to piece together a picture of the crimes. Time passes, and there is no news about Chet and Biff. Will the young detectives be able to get on the trail of the criminals and solve the mystery of their missing friends??