After days of heavy rain, eleven-year-old twins Josh and Lizzie Parker, and their travel-blogging parents arrive at the Jacksons' home in Welshburg, Ohio, an area famous for ancient mounds. Their son, thirteen-year-old William, a prize-winning rock hound, is a candidate for The Ohio State University's All-Star Science Camp, a prestigious program he's longed to attend. But recently, William has lost all interest in rocks, and now he's into soccer, playing striker, with disastrous results. Josh suspects the cruel taunts of Brady Yoder, a neighborhood bully, are responsible. Suddenly, the twins learn of a golf course development deal that could endanger the historic area. The Yoders can't wait to sell their land to developers, and the sale seems certain to succeed. Occasionally, rain reveals artifacts long hidden near mounds, and the treasure-hunting twins hope a discovery might rekindle William's interest in rocks and disrupt the deal. But who else is looking for treasure, and what other surprises does the land hold? Readers aged 8-14 years old will relish this exciting mystery set in Central Ohio. Strong characters who overcome bullies, stand up for the environment, and bravely forge their own path forward will entice readers of every age, including reluctant readers, parents, and educators.