The Alden children, isolated in a storm at a small bus station, are led into a mystery centering on a polluted river.

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 over...

Lemony Snicket investigates his own possible murder after receiving a note under his door stating that his breakfast was poisoned.

Teenaged detectives Joe and Frank Hardy uncover a plot to sabotage a ski resort.

Twelve-year-old Steve is investigating a diamond heist but the case suddenly changes when the author of the Bailey Brothers detective novels writes him a letter to say that he fears for his life.

Jessie Alden likes her new role at the student newspaper, but when a new boy at school comes to her with information about strange things taking place at his parent's business, she realizes her story is much bigger than she thought.

"Nancy investigates her father's disappearance in Washington, D.C. in the twenty-second book of the Nancy Drew Diaries"--

When the Alden children accompany their grandfather on a trip to Seattle, they discover clues throughout the city, seemingly planted just for them.

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

When someone steals the proceeds of a charity gala aboard a restored riverboat, it's up to Nancy, Bess, and George to find the thief before the clock runs out.