Two young sleuths look into a series of mishaps that are plaguing the 66th Annual Red Bluffs Roundup. Is it deliberate mischief or just bad luck? When fifth-grader Tommy Price and his rodeo clown father arrive in Red Bluffs, Tommy isn't thrilled to meet Bonnie Sue Hood again, but she catches his interest with her dramatic report that ""weird stuff"" is going on. Aging, superstitious country-singer Mel Jones seems most affected: an ""S"" appears before his first name on the program; he falls through a hole in the stage; and after his hallowed guitar disappears, he drives off in a panic--leaving his banjo-picking chauffeur, George, to provide the rodeo's musical entertainment. Latch when Tommy catches George with Jones' guitar, George admits being the culprit. Bonnie Sue, flushed with triumph, decides to form a detective agency. A low level of violence and plenty of slapstick compensate for the mystery's obviousness and easy resolution. Rosales' pencil drawings feature lots of horses, plus a charging bull that livens up the rodeo background.