Summary: "Danger!" says the ominous message written on a water park locker. Seth and Julia can’t pass up a mystery, and they accept a secret mission from an unknown gamemaster. While the mission has them solving riddles and decoding hidden messages, Seth and Julia investigate the gamemaster, including something called Operation Neptune. Does the gamemaster work for a top-secret agency? What’s Operation Neptune, and what does it have to do with Water World? Join Seth, Julia, Tyren, and Gabriela as they follow the gamemaster’s secret mission to its shocking conclusion!
 
Ages: 8-12
Themes: Forgiveness, Family
Featured Ride: Water World slides
 
About the Series: The Waldameer Mystery Files children's book series, set at Waldameer & Water World in Erie, Pennsylvania, was written with teachers in mind. The children's books teach empathy and diversity by including multicultural characters and immigrant and refugee characters who are learning English.