The "hollow ghost" haunting Chicago P.I. Malachy "Mal" Foley's dreams is Lammy Fleming, one of Mal's high school classmates. Mal, a new kid in school, had befriended Lammy at first, but Lammy was slow, chubby, bad at schoolwork, and terrible at sports, and he was the target of taunting and worse by the other boys at St. Robert's. Eventually, swayed by the cutthroat crowd of adolescent boys, Mal found himself unwilling to challenge the pack by championing such an unpopular boy. The way Mal turned his back on Lammy, the way Lammy became an invisible boy, has haunted Mal for more than twenty years. Now Lammy has been accused of assaulting a young girl in his neighborhood, and though the legal case against him is slim, the neighbors have already tried the case. Lammy is facing harassment, vandalism, and threats of worse. Mal's conscience has decided that clearing Lammy's name and protecting him against attack will lay Mal's guilt to rest. But challenging the girl's story - and her powerful Chicago mob father and uncle - proves much more dangerous than any twenty-year-old ghost.