From the publisher:
Dunkum loves mysteries. And when he digs for buried treasure, he uncovers one—in a mudhole! A locked box, covered in squishy mud. The discovery turns out to be a time capsule, buried many years ago.

Curious, the Cul-de-sac Kids search their muddy prize for clues. Who buried the time capsule—and why?

Dunkum and his friends are in for the surprise of their lives!