Dr. E. Mansfield Gunn

World War II veteran of the New Guinea campaign who kept American soldiers alive in some of the nastiest, most disease-ridden jungles in all of Australasia. Brought into CIA after the war, he was a bigwig in MK-ULTRA, mostly doing recruitment in research centers and universities, looking for developments in brain hacking and neurobiology.

Brusque and a bit arrogant, Dr. Gunn led the brain-hacking assisted interrogation of Sebastian Keiner at Granite Peak. Marshall finds his methods a little heavy-handed.