Something strange is happening to the sixth grade—and it’s up to student scientist Wilmer Dooley to crack the case in this hilarious mystery “filled with entertaining twists and nutty characters” (Publishers Weekly). If there’s one important thing Wilmer Dooley’s dad always says, it’s this: “Where are my car keys?” Okay, maybe not that. He also says: “Observe!” Wilmer has always known that the greatest science comes from the keenest observations. So when he observes his classmates looking a little green…and orange...and chartreuse-fuchsia polka-dotted...he knows that it’s up to him to find the cause of this mysterious illness—and its cure. But with his arch nemesis, Claudius Dill, hot on his heels; the eagle-eyed biology teacher, Mrs. Padgett, determined to thwart his plans; and a host of fluorescent classmates bouncing off the walls at increasingly dangerous speeds, can Wilmer prove he has what it takes to save the sixth grade from a colorful demise before it’s too late?