Twins Penny and Nix Albright grew up doing everything together. But when Nix dies in a tragic accident soon after college, she leaves behind a cryptic voicemail that has Penny guilt-ridden. Five years later, Penny has found new purpose as a rookie cop. She’s working to fulfill Nix’s dream of making the world a safer place. But following that dream becomes a nightmare when she’s called to her first murder scene. When she sees the victim, she knows him instantly: Danny Bowery, one of three men she’s long blamed for Nix’s death. A stunned Penny discovers a blonde in blood-drenched clothes gripping a box cutter. Before Penny can arrest her, the woman reveals that Bowery’s murder is part of a larger story that is far from over. Then she disappears. Now, Penny will stop at nothing to pursue this dangerous woman and learn why she’s avenging Nix’s death.