The Clue at the Bottom of the Lake — Kristiana Gregory

Action! Intrigue! Cliffhangers! With a riveting overarching series storyline and a mini-mystery in each title, Cabin Creek gives readers what they crave: immediate answers AND ongoing suspense. Every book reveals clues, adds layers, and finds the characters investigating, plotting, and unraveling clues. They'll need their wits, their courage, and their gadgets to get to the bottom of the many mysteries of Lost Island and Grizzly Paw Wilderness.

This is #2 in the series.