Frank and Joe Hardy receive an unusual assignment from their detective father. They are to "break into" the house of a Bayport neighbor, Malcolm Wright and retrieve a top-secret invention that the scientist had hidden in his study before leaving for California. The invention is in danger of being stolen and the boys race against time to beat the thieves at their own game. The young detectives soon discover that they are involved in a mystery far

When Sherlock and Amyus Crowe, his American tutor, visit Sherlock's brother Mycroft in London, what they find shocks both of them to the core: a locked room, a dead body, and Mycroft holding a knife. The police are convinced Mycroft is a vicious murderer, but Sherlock is just as convinced he is innocent. Threatened with the gallows, Mycroft needs Sherlock to save him. The search for the truth necessitates an incredible journey, from a railway station