When introverted rocket mechanic Joe and brilliant astro-botanist Fran are brought together to prepare for the inaugural launch of the world’s first-ever plant-fueled rocket, there are immediate sparks, but neither is particularly adept at romance. Life becomes more complicated when three aliens take refuge in Joe’s home. Dunk, Welly, and Shirm are on the interplanetary run from a zealous-yet-inept officer of the law named Zandro. The aliens determine that Fran’s rocket could provide their means of getting back home to safety.