Frank and Joe Hardy's efforts to retrieve a top-secret invention from a scientist's house in Bayport leads them to a mystery involving a dangerous gang of jewel thieves and smugglers.

As more and more of his flowers display the bite marks of a wandering tortoise, Nate sets out to uncover the mystery of the reptile's origins.

Everyone knows that 7 is always after him. Word on the street is that 7 ate 9. If that's true, 6's days are numbered. Lucky for him, Private I is on the case. But the facts just don't add up. It's odd. Will Private I put two and two together and solve the problem . . . or is 6 next in line to be subtracted?

"Cursed by an old carnival game, sixth-grader Rex Dexter uses his new ability to communicate with dead animals to investigate the mysterious deaths of endangered zoo animals"--Title verso page.

The stories illustrate how Frank and Joe Hardy use the various facets of police technology while tracking down criminals. Techniques include fingerprinting, surveillance, and other related skills in the science of criminal investigation.

"Nate the Great and his trusty dog Sludge, have a tricky case to solve. Nate's friend Rosamond has started a future-telling business, but her money box is missing. Sludge and Nate visit Claude, who helped Rosamond set up her business, and Finley, who collects boxes for his rat. They can't seem to help. It looks like the only way to clean up this case is to get down and dirty in the dumps!

Nancy Drew and the gang set out to solve the mystery of their disappearing snowman, Sherlock, after her new friend Deirdre's fortune-telling predictions start coming true.

The Boxcar Children are spending the summer in an enormous New England farmhouse. There's an old woodshed near the house that holds a surprising secret--a secret that dates from the Revolutionary War. Suddenly their summer becomes an adventure.

"Amateur sleuths Frank and Joe Hardy investigate a counterfeit operation while their detective father is connected to a secret case involving national security. An old mill on the outskirts of town appears to hold the key to solving both crimes"-- "Amateur sleuths Frank and Joe Hardy investigate a counterfeit operation while their detective father is connected to a secret case involving national security. An old mill on the outskirts of town appears...

"When twelve-year-old Logan Wilde wakes up to discover a baby griffin hiding under his bed, he suddenly finds himself thrown into a mystery involving his classmate Zoe Kahn and a magical menagerie right in the middle of his sleepy Wyoming town"--