What if love left a physical trace? A unique, measurable signature on the human heart, as real and irrefutable as a fingerprint.

For brilliant cardiologist Dr. Aris Thorne, this discovery is the holy grail—scientific proof that the connections we forge are embedded in our very biology. Her experimental scanner can detect these “Heartprints,” the beautiful, resonant echoes of love left behind in the heart’s tissue. But when she meets Ben Carter, a charismatic book restorer who reawakens her own guarded heart, her miraculous discovery becomes a terrifying mystery.

A scan reveals that Ben’s heart carries two prints: the new, bright signal of his connection with Aris, and beneath it, the faint, haunting echo of a woman who vanished from his life years ago.

At the same time, a series of flawless, untraceable deaths are rocking the city. Healthy, powerful individuals are dying from sudden cardiac failure, leaving no evidence of foul play. Drawn into the investigation, Aris makes a horrifying discovery: each victim has a "Signal Scar"—the violent, shredded remnants of a Heartprint that has been purposefully erased.
Her beautiful discovery has been turned into the perfect weapon.

Now, Aris is trapped in a desperate race against a ghost from the past—a killer who understands the science of the heart even better than she does. With every step she takes to unravel the conspiracy, she sinks deeper into a web of love and obsession where her own heart is the ultimate prize. To save the man she is falling for, she must hunt a killer who can hear her every move, feel her every fear, and who is determined to prove that the only love that endures is the one that can never be erased.