Everyone can fly except the girl called Gurl in Ruby's (Lily's Ghosts
) utterly odd and charming modern fantasy. Living in the horrid Hope House orphanage, Gurl accidentally discovers that although she's alone in being earthbound, she can make herself invisible. The House's greedy matron, Mrs. Terwiliger, exploits her newfound gift by making her steal expensive clothing and jewelry. Such drama pales, though, in comparison to the threat facing her in the form of Sweetcheeks Grabowski, a ruthless gangster with a background as a diaper model; Sweetcheeks knows of Gurl's existence and wants to kidnap her to help him steal a priceless pen. The book is inspired silliness from start to finish. Several scenes are laugh-out-loud funny, such as when a team of hairdressers mistakes Gurl for a member of the theater and gives her a makeover. The conclusion, in which it is explained that the pen Sweetcheeks is after has the ability to make anything it writes come true (which is tied to the origins of how people learned to fly) would seem out of place or thrown together in another book, but here readers will likely agree that it seems both appropriately goofy and tongue-in-cheek. Ages 10-up. (Mar.)