A schoolboy living in the suburbs of London in the 1960s experiments with murder and is packed off to a hospital for the criminally insane for eight years in this black comedy by first-timer Benjamin Ross, who collaborated with Jeff Rawle on the screenplay. I’ve tried twice to get to the end of this glib, formulaic exercise and failed both times. With Hugh O’Conor, Antony Sher, Ruth Sheen, Roger Lloyd Pack, and Charlotte Coleman. (JR)