A detective with a big heart and a deadly aim. A forensic psychologist whose loyalty could get her killed. A ruthless killer out for revenge.

Denver Detective Grady Thorne has found a new home in the DPD. He has a partner he trusts, a unit he respects, and a boss he admires. Then there’s Izzy. Smart, sexy, and willing to keep things casual, the mouthwatering psychiatrist’s no-strings arrangement is all Grady needs...or so he thinks. But this reluctant detective is about to realize just how far he’ll go for the woman threatening to break through his long-standing defenses.

Dr. Isobel “Izzy” Garcia knows what it’s like to be failed by the system. Thanks to her broken past, she's gone through life refusing to let anyone get too close. Especially the sexy-as-sin Detective Thorne. Before now, their secret, friends-with-benefits agreement has given her everything she needs. But when Izzy and her estranged brother find themselves in the crosshairs of a killer, she'll do whatever it takes to protect the only family she has left. Even if it means putting her life—and heart—in Grady’s hands.

With danger knocking on Izzy’s door, Grady vows to keep her safe. But time is running out, and if they can’t find the person behind the attacks on her life in time, it’ll be too late for them all. Because the man they’re after is driven by a deep-seated revenge, and he won’t quit until Izzy’s guarded heart stops beating…forever.