Doc Rios is the medical officer aboard the USS Nathan James. His rank is that of Chief Petty Officer (E-7) in the U.S. Navy. While Rios has significant medical training, he is not a physician, and the name Doc is more of an honorific.Rios assisted Dr. Scott during her testing on volunteer human subjects for the cure. When Maryland State troopers took the ship hostage on orders from Amy Granderson, Rios smuggled the Primordial strain of te cure out of the lab in his medical kit. While tending to Dr. Quincy (who was shot by a trooper while trying to protect the lab), he let Slattery know that he had the Primordial and Slattery hid it when the troopers were distracted, in a place suggested by Quincy. Rios kept Quincy alive even though he had a near-fatal abdominal wound; Quincy killed himself by removing the plug that kept him from bleeding out, rather than tell the troopers where the Primordial strain was hidden.Rios tended to the prisoner they took from the hospital ship Solace; this prisoner was one of the crew on the British Navy ship that was hunting the Nathan James in an effort to destroy the cure. Rios asked Dr. Rachel Scott to surgically remove what they thought might be a beacon lodged in the chest of the prison, who had started coughing up blood, since Dr. Scott had more surgical experience. After they removed what was actually a flash drive, Rios tended to the prisoner's post-surgical care. Show less «