At a Moody family yard sale, Stink uncovers a box of old comics about a hero he’s never heard of: Super Gecko. What could be more fantastic than a superhero with lizard superpowers? Hello, fun! Even better, Super Gecko is making a comeback, and Stink quickly becomes his number-one fan. Stink starts receiving mysterious notes signed by Super Gecko himself. But Super Gecko isn’t real, is he? Using his own powers of deduction—thanks to all the cool stuff he’s learning at Saturday Science Club—can Stink figure out who is writing the letters?