Black Diamond, a fictional champion racehorse, goes to a prison equine rehabilitation center after a career-ending injury, in this tale inspired by real-life prison programs. A young inmate, Blake, befriends him, and—happily-ever-after—adopts Black Diamond upon his own release. Unfortunately, Blumenthal’s black-or-white attitude stacks the narrative deck: Black Diamond is a champion racehorse, not an ordinary one; a sinister man “with a fat wallet” tries to buy Black Diamond before the rehab program does (why would this be bad?); the prisoners other than Blake treat Black Diamond harshly (so the rehab program is inhumane?); Blake is in prison for stealing money to help his out-of-work father support the family (only prisoners with noble motives are worthwhile?). These extremes manipulate readers’ emotions without presenting a realistic picture of such programs for readers. Overly sentimental third-person narration in Black Diamond’s voice includes such clunky lines as “in a minute that grew heavy with time.” Hyman’s lovely pastels provide a 1950s feel, which seems at odds with the modernity of the rehab programs. (author’s note) (Picture book. 5-8)