Chickadee Lake is a magnet for vacationers in Lancaster’s idyllic summer—especially when people start sighting a strange creature in the water. When Elaine and Jan host Jan’s twin grandsons for a week, the boys see the monster for themselves, and game warden Jack Weston is called in to help track down “Chick,” as the residents nickname it. Jan and Elaine set out to investigate and turn up some clues suggesting someone has recently built a “monster.” But who? And why? Meanwhile, as the twins occupy themselves with Vacation Bible School and collecting turtles around the lake, the town’s volunteer firefighters prepare for their traditional firemen’s muster, which will help raise much-needed funds for new equipment. But when the cash box is stolen from the event, the whole town is set on edge. Are the sightings of Chick just a diversion to keep the town occupied while a crime takes place—or is something else going on?