Calendula Cool

The picturesque seaside city of Calendula (pronounced Ka-len-doo-la) occupies the southern curl of Camino Bay, in California’s rugged central coast.

During the last days of fifth grade, a rumor races around school that a girl vanished in the local forest. The totally secret Mysterious Adventures Society sets out to investigate. Possible clues include a porcelain figurine of a sailor, a drama script from school—and an old rope trailing over the edge of a seaside cliff.

But they’re not the only...