FBI Special Agent Matt Roarke has one of his agents undercover, closing in on a major criminal organization, when he witnesses his agent being killed before his eyes on a busy street in San Francisco. He questions whether it is accidental, especially after having seen a mysterious woman at the scene. After further investigation, he finds other supposed accidents and murders that included this woman being on scene. Roarke finds himself on a multi-state journey to track this woman and figure out whether he's got a potential female serial killer in his sights.I really enjoyed this story as it involves two pursuits, tracking this mysterious woman and determining if these accidents are really crimes and how the victims are connected. We also get to see part of the story from this woman's point of view, which makes it even more intriguing. There are a few twists and an air of mysticism as Roarke seems to have unusual instincts and connections. He's an interesting character, along with his partner, Damien Eppes.The story is so well paced and I loved how details slowly unfolded, each new reveal adding a layer of complexity along with the resolutions. I'm reluctant to say much more as it could spoil others' reading experiences. It's well written and I'm in for the next book. I highly recommend adding this to your bookshelves.