The Obsidian Files 8: The Doctor and the Patient. The Obisdian Files, #8

The disease is a conspiracy. The cure is a choice. And the only man she can trust is the patient she must kill. Dr. Olivia Foster has dedicated her life to the forgotten and the forsaken. When an eight-year-old boy arrives at her free clinic with a mysterious, incurable illness, she refuses to accept the diagnosis. Her obsessive search for answers leads her to a quiet, unassuming patient named Noah, a man with haunted eyes who knows more than he lets on.
He gives her a key, a search engine that unlocks a dark corner of the Obsidian data dump, revealing a horrifying truth: the boy's disease is not a natural affliction. It's a failed genetic experiment. Noah is more than just a guide; he is the last living success story of Project Chimera, a secret program to create genetically enhanced super-soldiers. He is a man at war with the monster in his own blood, and the sick little boy is a beacon that will lead the conspiracy's new leader right to their door.
Forced into a desperate alliance, the idealistic doctor and the haunted weapon must race across the country to find the other lost subjects of the experiment and deliver a cure. Their mission is a frantic journey into the heart of the conspiracy, and a slow, tender fall into a love that is as impossible as it is undeniable. But when the cure Olivia creates is revealed to be a potential death sentence for Noah, they are forced to confront his monstrous past.
To save the woman he loves, Noah must make a terrible choice: embrace the weapon he was designed to be and face his own father. But in the heart of the enemy's fortress, the ultimate betrayal awaits, leaving Olivia with a gun in her hand and an impossible choice: save the man she loves, or kill the monster he has become.