Twelve-year-old Meg Pickel hasn’t slept a single night in the six months since her 15-year-old brother Orion mysteriously disappeared. One night, a green glow emanating from the vacant Satis House—and the hope of finding her brother—lures her across London’s rooftops to investigate. Through the skylight she witnesses a phony séance, Dick Whittington’s unsummoned ghost… and… was that Orion? More astonishing still, Charles Dickens—a dear Pickel family friend and print-shop customer—happens to be on the rooftop, too, in search of fodder for his next novel. Together they vow to find Orion, and thus begins this deliciously elaborate, slightly overcooked adventure, generously spiced with Dickensian characters and dished up in a conspiratorial storyteller’s voice. Playful allusions to children’s books not yet written in 1862 (such as Peter Pan and Redwall)—and even silly nods to Monty Python—pepper meaty subjects from London’s cruel workhouses teeming with stolen children to humanity’s “haunting” moral obligation to combat injustice. The sights, sounds and stenches of 19th-century London are palpable even without the moody black-and-white illustrations. (note on “Children and Charles Dickens”) (Historical fiction. 11 & up)