EDGE

In Clark's run-of-the-mill fourth case for Chicago police detective Harriet Foster (after Echo), suspicion still trails Harriet after the murder of Eddie Noble, who killed her former partner, detective Glynnis Thompson, and vowed to kill Harriet before he died. With the Noble case hanging over her head, Harriet is drawn into a new investigation after spotting two overdose victims in a locked city park. One is dead by the time Harriet reaches him, but she manages to revive his companion, 19-year-old college student Ella Byrne, whose uncle, Matt Kelley, is one of Harriet's colleagues on the force. The overdoses prove to be among the first of several linked to a new street drug called Edge, and Harriet sets out to find its source--though her determination to use official channels is complicated by Matt's thirst for vengeance. Meanwhile, there are power struggles within the Gamons, a sophisticated street gang responsible for distributing Edge across Chicago. It's all a bit too familiar, and Clark's overwrought prose ("Grief stills the wings of even the strongest bird") is little help. Not much here is memorable. Agent: Evan Marshall, Evan Marshall Literary. (Dec.)