Rene Schwartz ended a twelve-year career as a federal agent working Witness Protection when a subordinate went rogue and lost her life. Rene left the job she loved to manage her guilt and regret. Working as a private investigator with HEARTS has given her a chance to use her skills—but not to heal her heart.

Quinn Stanton found his ex-wife murdered in her home. While he was cleared of any involvement, he and his six-year-old son Danny definitely aren't safe. After a series of suspicious break-ins at his house, Quinn decides he needs the one thing the police—including his twin brother—can't provide: protection.

With Quinn and his son in a safehouse, the HEARTS team tries to unravel the mystery of who killed Eliza Stanton—and who could possibly want Quinn and Danny dead. But as secrets come to light and passions ignite, protecting each other may be the one promise Quinn and Rene can't keep.