A mystery envelope, a riddle, and time is running out...

A strange blue envelope greets the kids of Coral Canal right before Labor Day weekend. Inside it contains a riddle and a set of instructions. Nobody, not even their parents, seems to know who sent the riddle, and the children only have five days to solve it and send photographic proof.

With hard work, humor, and perseverance, Marisa, Avery, Enrique, and friends attempt to fulfill the riddle's demands. Kayaking, paddleboarding, and hiking through mangrove islands, they scour the area. But Marisa's need to win at all costs leads to a dangerous situation. Can she learn to let go of perfection before her determination puts everyone at risk?

Fans of faith-filled favorites like The Secrets of the Hidden Scrolls and Imagination Station will love Key's Secret. They won't be able to put the book down until THE END and will be left wishing for the next riddle!

Key's Secret is the fifth book in the Apex Adventure children's series.

Solve the riddle. Unlock the adventure!