Dan receives a copy book in his box. There’s no additional info to help him figure out what it means, but the listener is clued into a scene of a murder where the killer seeks for a missing copy book. When Dan gets a following letter about a missing copy book, his curiosity starts him on the trail of this mystery.

Just what is a copy book? It’s a notebook for kids to copy down their lessons, and generally write or draw in. When Dan meets the couple claiming to be the parents of the child behind the missing book, their stories are so full of lies that Dan decides to figure who the real owner of the book is before he lets it go so easily. Back in his office he spends an all nighter pouring over the book, looking for some secret code or message. There’s a shadowy figure in the dark with a knife. A struggle, and Dan is left with only a knife to present to the cops to check for fingerprints.

The notes in Box 13 about that copy book keep coming. Might this be the real owner? The plot twists keep coming, but this just might be the twist that helps unravel Dan’s mystory.

Whatever is behind the book, it is shrouded in more than one death, and plenty of secrets. It involves an old archaeology expedition to South America and Mexico, but listen in to get the clues first hand, and try to solve the mystery.