"Billy and Manny know exactly what Sure Things, Inc.'s next big thing will be - a hovercraft! But when they start to build it, they notice it's a little...haywire. The hovercraft dips, dives, twirls, and spins, until one day, it's gone entirely, and so is Emily! Can Billy find his sister and fix the hovercraft, or will this be a crash landing for Sure Things, Inc.?"--Jacket.