Summer vacation is here, and Lizzie's less than thrilled. Why? Because her parents were less than thrilled with her report card-so they're sending her to science camp. Ugh! Luckily, her best friend, Gordo, is going to Camp Bunsen Burner, too-but not because his science grades are weak. He's actually excited about going. Gordo even enters the camp's Best Invention competition. And that's the reason he needs Lizzie's sleuthing help . . . . Someone has stolen Gordo's entry-a brilliant formula for glow-in-the dark mosquito repellent. Is it Larry Tudgeman? Or the suspicious (but very cute!) camp counselor? Or could it be the chemistry teacher himself? Lizzie promises to help Gordo find his formula-and, in return, maybe he'll find a way to get her outie!