Brother detectives Frank and Joe go full-steam ahead to find the truth in the twenty-third book in the thrilling Hardy Boys Adventures series. The Hardys and some of their friends hop aboard an old train that’s been restored and turned into a murder mystery experience. A cast of actors will perform an immersive theatrical production while passengers dine in style, assume roles in the game, and ultimately try their hand at solving the case. This should be a cakewalk for Joe and Frank! The production is a mess. The actors are lousy, fumbling their lines and spelling out obvious clues. At least the food is pretty good. But just as the Hardy Boys are trying to make the most of a disappointing situation, one of the cast members goes missing. At first, the audience thinks that the show is taking a turn for the better, but it quickly becomes clear that this is not part of the act. For the Hardys, the mystery has gone from good fun to deadly serious. And trapped on a train full of people who aren’t who they say they are, everyone is a suspect. Will Frank and Joe be able to figure out how someone can vanish into thin air on a moving train before this case goes completely off the rails?

"What Happened At Midnight" is an exciting mystery novel by Franklin W. Dixon. The story revolves around the adventures of the Hardy Boys, Frank and Joe, who are skilled amateur detectives always eager to take on challenging cases. The plot begins with the Hardy Boys receiving a mysterious message requesting their assistance in solving a perplexing and dangerous case. Intrigued, they set out to unravel the enigma and uncover the truth behind the strange events that occurred at midnight. As the brothers delve deeper into the investigation, they encounter a series of thrilling escapades and encounters with suspicious characters. From hidden passages to cryptic clues, the Hardy Boys use their intelligence, bravery, and quick thinking to navigate the twists and turns of the case. As the story unfolds, the brothers find themselves entangled in a complex web of deception and danger. They must rely on their detective skills and work together to decipher codes, follow leads, and uncover hidden secrets. Throughout their quest for the truth, the Hardy Boys face various challenges, including narrow escapes, daring rescues, and unexpected revelations. With every clue they uncover, the mystery deepens, and the stakes become higher. In their relentless pursuit of justice, Frank and Joe race against time to solve the puzzle before the clock strikes midnight once again. The climax of the story is filled with suspense and excitement, as the Hardy Boys finally uncover the truth behind the mysterious events that took place in the dead of night. "What Happened At Midnight" is a thrilling and engaging mystery that keeps readers on the edge of their seats from start to finish, showcasing the bravery and resourcefulness of the Hardy Boys as they solve yet another intriguing case.

A sleek new hydrofoil is scheduled to start ferrying passengers between Bayport and Cape Cutlass. But business enemies of the hydrofoil owner have stirred up a hornets’ nest of violent opposition among small boat owners. Fearing sabotage, he begs Frank and Joe Hardy to guard the Flying Express on her maiden trip. Startling developments plunge the teenage detectives into a dangerous chase by sea, air, and land in pursuit of a gang of hardened criminals who operate by the signs of the Zodiac. Tension mounts when the Flying Express vanishes – and so does Sam Radley, Mr. Hardy’s skilled operative. Peril stalks Frank and Joe’s every moves as they hunt down the terrifying gangleader Zodiac Zig and his vicious henchmen.

After the new hydrofoil they are guarding is stolen, the Hardy boys face frequent danger in solving a mystery involving criminals who operate by signs of the zodiac.