For Mabel Crockett, the town of Logjam is a fine place to grow up. Sure, some folks are constructed of spare parts, and her own family flies around in a converted WW2 bomber. And over at Halfslips' Center for Botanical Research they're always growing something new and surprising. Not until the creepy Verdon Arbogast begins poking around does Mabel begin to suspect that something really peculiar is going on. Then Mabel receives a cryptic message, and discovers that it's up to her to unravel the secrets of Logjam. Secrets which might reveal more than Mabel wants to know...about herself.