The mystery of the giant brother-stealing robot may have been solved, but a new set of troubles for Molly and her friends has just begun. Strange things are happening once again in Far Flung Falls. Where have all the pets gone? And who--or what--is behind the disappearances?

Naturally, everyone is looking to Molly for answers. Only this time, she's as clueless as anybody else. What's more, between dad's new girlfriend, fifth grade homework, and her friend Margo's wild schemes, Molly's already got more than enough to deal with. Still, she feels the pressure of everyone's expectations, and that pressure only mounts when the list of vanished pets grows to include her beloved cat, Crank.

Determined to find her, Molly hops back on her revamped bike, Pink Lightning, and together with Arvin, Leonard, and a few new faces, Molly sets off in search of answers. But nothing can prepare them for what they find...or what to do when it finds them.