A child dies in the hospital shortly after the infectious disease consultant, Dr. Michael Grant, evaluates her. The 35-year-old physician has cause to be troubled by the patient's death. He failed to perform a careful examination, did not check the results of her most recent lab tests, and held off on ordering antibiotics. Although an autopsy was not performed, it is believed she died of sepsis.

Divorced and recently relocated to North Carolina, Dr. Grant is already depressed. Now he must worry about the possibility of a malpractice lawsuit. Jonas Williams, the father of the dead child, is also ill. He complains of fatigue, visual disturbances, confusion, night sweats, and fever. Jonas has developed unusual lesions in his throat and retina--white threads in a serpentine pattern. A biopsy of his oral lesion demonstrates the presence of osteoblasts and new bone formation. Dr. Grant becomes convinced he has stumbled onto a completely new infectious illness even though he cannot identify the causative organism.

Jonas experiences gastrointestinal bleeding as a result of a low platelet count. He dies in a trailer that has caught on fire. Dr. Grant soon develops the same symptoms as his patient. He remembers coming into contact with some of Jonas's blood. He is admitted to the hospital with massive gastrointestinal bleeding. His physician attributes the bleeding to ulcers, gastritis, and thrombocytopenia. Dr. Grant, however, believes the bleeding is due to the same mysterious disease that Jonas had.

The body of Jonas's daughter is exhumed, and there is anatomic evidence of the same bizarre changes that occurred in her father. Dr. Grant visits a cabin in the woods where Jonas had lived. He is looking for clues to the puzzling new illness. What he finds, however, is not an answer. Instead, it is a renewed appreciation for his life as well as the world around him.