"I am going to put your life in order, Sienna." Sienna is an exhausted, underpaid reporter desperate for her big break. When a bloody cartel ambush erupts outside her Hell's Kitchen apartment, she thinks she's finally found her story. Instead, she finds Special Agent Benjamin Poindexter Dex is the FBl's deadliest sniper-awkward, rigid. When Sienna approaches his crime scene, his fractured brain latches onto her vulnerability. Soon, he is watching her through her window and reading her classified files. When he uncovers her dark, abusive past, his obsession solidifies into a terrifying mission: Sienna is chaos, and Dex will become the permanent structure in her life. Whether she wants him to or not.