David Thomas is an emergency department nurse who was converted to being an ambulatory care nurse when he returned from deployment to find that his job had been more than adequately filled by his protégé. Ambulatory care has given him experience in various primary care areas including aviation medicine, occupational health, urgent care, and dental. He is now a deputy director for medical services, which encompasses pediatrics, family medicine, internal medicine, mental health, emergency room, immunizations, optometry, respiratory therapy, gastroenterology, substance abuse rehabilitation, cardiology, neurology, and dermatology.