Vande Velde (Never Trust a Dead Man, p. 458, etc.) combines a ghost story with slave history for a comic middle-grade novel. Fifth-grader Ted has an obnoxious teenage brother, Zach, and a cute five-year-old sister, Vicki, who seems to attract ghosts. Her announcement that she has a new invisible friend, Marella, is followed by another pronouncement, that Vicki is afraid of a “bad lady” who is also invisible, but who comes through the walls. Ted has a series of vivid nightmares about corpses trying to drown him; when his school project on Luxembourg is wrecked by apparently unseen hands, he’s convinced the house is haunted and begins digging for clues. Ted learns his house once sheltered runaway slaves, and identifies the ghosts as mother and child fugitives who drowned in an old section of the canal behind the house. A description of the real-life mother in an old diary indicates that she was a good person—has she turned nasty in the afterlife? In a surprising twist, it is Marella who must fulfill her sinister purpose and possess Vicki. Ted, a witty narrator on the subject of the typical sibling behavior that is spiked into the plot, must submit to possession himself, in a fast-paced story that mixes scares and history for some can’t-put-it-down fun. (Fiction. 8-12)