Mandie and the New York Secret
Mandie, Joe, and Celia arrive in New York, eager to see their friend Jonathan and learn the secret he has discovered. But they no sooner arrive than find out Jonathan has gone off to Long Island! Wild with curiosity, Mandie isn't sure she can wait for his return. Surely there's a clue somewhere ...

Mandie and the Night Thief
A visit to their friend Tommy Patton's home in Charleston finds Mandie and the others in the midst of another mystery. Strange noises from the third floor have convinced some of the servants that the house is haunted. Then Mandie's jewelry starts to disappear. Who -- or what -- is in the house?

Mandie and the Hidden Past
When Mandie learns of a crack in the wall of the secret tunnel beneath her house, she's convinced it holds a mystery. The further she investigates, the more everyone keeps her away, making Mandie more determined than ever. But what she finally discovers may be better left buried!