The Secret in the Old Lace — Carolyn Keene

A mystery magazine is offering a prize to anyone who can solve a century-old mystery: what happened to the dashing Belgian gentleman who vanished into thin air one hundred years ago. Nancy is sure she can win -- until her entry is stolen and the game turns deadly serious.

Determined to solve the puzzle, Nancy flies to Belgium in search of the startling truth. The only clues are the fragments of a burned letter and a pair of beautiful lace cuffs. Nancy uncovers a bizarre tale of star-crossed lovers and hidden treasure. But someone is out to throw her off the track ...and to make sure she can never reveal the dark secret in the old lace.