Something truly spectacular has just arrived in Green Lawn. A traveling circus has set up its tents, but the performers are in big trouble. Their show is disorganized, their equipment is broken, and they desperately need some help. Best friends Bradley, Brian, Nate, and Lucy are happy to chip in and fix things up for the acrobatic troupe known as the Flying Fortunatos. They manage to find dazzling new acts for the show, but what the circus really needs is a brave acrobat to perform on the incredibly high trapeze. No one in town wants to risk the climb, except for one mysterious person wearing a mask. The kids realize that if they can figure out the identity of this secret high-flyer, they might just save the entire show. You will be hooked on this circus adventure as the young detectives solve the puzzle under the big top.