Aisling's family has never been picture-perfect: abandoned as a child by her father, and still grieving her mother, Aisling's two sons are all she has left. For years, they'd felt like enough. Now, she needs answers. Desperate to find the truth - about her family, and herself - Aisling uploads her DNA to an ancestry website. She soon finds a match. But instead of her father, she's faced with Detective Jonah Sheens. He's investigating the latest in a string of murders by a serial killer. Aisling's DNA is a match for the crime scene, leaving the police with three suspects: her long-lost father, and her two sons. Aisling always swore she'd do anything to protect the little family she has left. But would she protect a murderer?