I enjoyed this solid debut of a mooted police procedural series featuring DCI Ronnie Carlson. “Tangent” finds Carlson and his crew hunting a particularly vicious serial killer who seems to be a blast from the past. Carlson, grieving a family loss, is an appealing, “everyperson” protagonist, and his crew of police are all drawn convincingly. Although the villain seemed to me to be less “alive,” and although the stylistics and plotting bounced up and down a bit in quality, overall I raced through the novel with quiet pleasure.