At the mercy of a killer. Overwhelmed with grief and anger, Special Agent Emma Last is now haunted by more than the ghosts who seek her out. Guilt becomes her constant companion as she attempts to unwind the clock, undo what’s been done to yet another person she loves. Will she ever escape the weight of her past? When a fellow agent rescues a little girl hidden in the tunnels under the Washington National Opera House, Emma finds a focus for her energy. And she’s determined to find the person responsible. Especially when two more children are found in the same tunnel network, their lives gruesomely claimed by blood-sucking leeches. With no clear connection between the young victims other than their impoverished backgrounds, the investigation hits a dead end. But Emma isn't alone in her quest for justice. She receives cryptic clues from ghosts that only she can see. The challenge for Emma isn't just finding the killer—it's convincing her team to believe her insights, especially with her reputation tarnished by recent transgressions. She’s on thin ice, but her resolve is unshakable. She can't—and won't—let another child's life end tragically on her watch. No matter the cost. Last Mercy is the seventh book in the suspense-filled FBI series by bestselling author Mary Stone. You’ll be at the mercy of your imagination as the curtain falls on one of the most horrific crimes yet.