The Secret Science Alliance and the Copycat Crook by Eleanor Davis
Super-smart Julian Calendar thinks starting junior high at a new school will mean he can shed his nerdy image–but then he meets Ben and Greta, two secret scientists like himself! The three form a secret club, complete with a high-tech lair. There, they can work to their hearts content on projects like the Stink-O-Meter, the Kablovsky Copter, and the Nightsneak Goggles.
All that tinkering comes in handy when the trio discovers an evil scientist’s dastardly plan to rob a museum. Can three inventors, armed with their wacky creations, hope to defeat this criminal mastermind?