When a sinkhole opens up and swallows one of Bayport's historic statues, Frank and Joe suspect something--or someone--shady at play. They jump at the chance to investigate ; Joe as a member of an urban exploration club, and Frank as photographer for the school paper. But in the thick of their search, the boys stumble upon an entire underground city that's been abandoned for years. Now the city is home to a cultish band of criminals who plan to take...

Frank and Joe investigate underworld crime at Bayport's new state-of-the-art health club.

" The Hardy Boys are visiting Paris! Joe is excited to check out all the street art he's heard about. And Frank can't wait to go to all the museums he's researched. On their very first day in the city, the brothers are woken up early in the morning by fireworks. But these are no ordinary fireworks. They are a part of elaborate cover for the heist of a priceless artifact. What's worse, the theft seems to have been orchestrated by Joe's favorite street...

While sailing a friend's yacht from Saint Martin to Florida, Frank and Joe become involved in a mystery involving a cargo ship, it's missing crew, and a secret cargo.

The Hardy brothers investigate after reports of a beast attacking people. Is the Bayport Beast real after all?

An original Sherlock Holmes manuscript was stolen from the Bayport Museum and now pages keep showing up in Frank and Joe's things: their lockers, menus, even the backseat of their car. It's clear someone is out to frame them. But who could it be?

When television wildlife celebrities Jumpin' Jack and his son bring their menagerie to Bayport Elementary, Frank and Joe are on the case for a boa constrictor that goes missing.

Frank and Joe's immersive murder mystery experience turns into a real missing person's case.

When new team members are being kidnapped and threatened, Frank and Joe join the basketball team at the request of their principal to uncover the culprits.

Detective brothers Frank and Joe work to solve a muddy mystery when the spring break Mud Bud Run is canceled due to a frog infestation.