Nickel is a 12-year-old abuse survivor living all alone in suburban Michigan. He sells marijuana and blackmails Internet pedophiles in order to fund his real profession: clandestine detective, complete with night-vision goggles, camouflage jumpsuits, a getaway bicycle, and some not-bad jujitsu skills. Most pressing among his current caseload is the pro bono mystery of an abducted little girl. She’s probably dead, but Nickel is determined to find out who did it anyway--and it doesn’t hurt that his client, the girl’s older sister, is one heck of a dame (“It was awful to see her go but nice to watch her leave”). Writing with a deaf ear to what’s fashionable in YA, Davis’ terseness initially comes off like hardboiled spoof and risks alienating readers with its steadfastly unemotional tone. Almost slyly, though, Nickel’s one-note voice becomes affecting; read between the lines and you’ll find a damaged kid whose defense mechanism is to be a crime-fighting robot. As dark as they get, Nickel’s travails are often laugh-out-loud funny: he’s got his plan, and he’s sticking to it. Readers will, too, right through the pulse-pounding climax and the crushingly offhand sadness of the denouement. Davis hits hard--but with a surprisingly light touch. --Daniel Kraus, starred review