Hayley LeBlanc is on the set of Sadie Solves It, the mystery TV show she stars in, when she comes across a strange and spooky discovery: a dead body! It sure looks like one at least, with feet sticking out from under a sheet. She races to go get a security guard for help, but by the time they get back, the body is gone! The security guard thinks she was just seeing things, but Hayley knows there was something there—and it’s really fishy that it disappeared. With the help of her friends, Hayley investigates. Can they figure out the mystery of the mysterious "corpse?"