Smashie McPerter and her classmates from Room 11 are going on a field trip to the planetarium! Nobody is more excited than Smashie's best friend, Dontel, who dreams of becoming an astrophysicist. In fact, Dontel has even created an accurate drawing of a working rocket, piloted by his and Smashie's favorite action figure, Brainyon. In a surprise move, Dontel's grandmother, who's chaperoning, brings the rocket drawing with her to enter into the planetarium's science contest. But in a shocking turn of events, the drawing goes missing before they get there! Smashie is on the case (luckily she brought an array of interesting hats to help get into character). But the suspect list keeps growing--prankster Billy, who prefers the Haddock over Brainyon; tight-lipped Tatiana, who's wearing a NASA T-shirt; and . . . Smashie herself? Nobody is above suspicion in this third hilarious and clever Smashie McPerter mystery.