Trixie Belden solved her first mystery more than 50 years ago, and her sleuthing skills have delighted readers ever since. For the first time enjoy FOUR Trixie Belden adventures in one collectible boxed set! Trixie Belden loves riding horses, exploring with her best friend Honey, and solving a good mystery! Which is good because trouble seems to follow her everywhere. But no secret lasts long when detective Trixie is on the case! The Secret of the Mansion: Trixie is settling in for one boring summer until a new neighbor, a run-down manor, and rumors of a hidden treasure make it the most exciting one yet! The Red Trailer Mystery: Trixie's road trip adventure hits a few bumps when a young girl goes missing and car bandits are on the loose! The Gatehouse Mystery: Trixie and her friends thought they found the perfect detective clubhouse, but when they uncover a diamond in the dirt, they worry jewel thieves might have gotten there first! The Mysterious Visitor: There's a new face in Sleepyside, but Trixie isn't convinced this guest is who he claims to be! Discover Trixie's first great mysteries in this beautiful boxed set that includes the original illustrated interiors!