The city tinged the water a deep, emerald green for the St. Patrick's Day Parade, which made the body floating through it even more gruesome. Moms' hands covered their children's eyes, as a second body came into view. A barricade of yellow crime scene tape was strung up. Dr. Cade Ashton looked over the scene below. The unnatural, intense green of the Potomac stared garishly back at him. His mission sounded simple. Find the source of the latest infection. The CDC (Centers for disease control) gave him little to go on. For one thing they were clueless. More dead bodies are flowing down the river. Dr. Frank Goya, who isn't who he seems, and Marla the journalist turned temporary scientific photographer try to help Cade find the source of what has killed several people. If they can't, more people will die.