Joe Gall is an assassin for the CIA.
Born of wealthy parents, he first saw action as a Marine Corps officer during World War II. It was while fighting in Iwo Shima that he 'caught a daisy clipper' (hit by machine gun fire) in his right ankle, resulting in months of recuperation. Even after his recovery, nasty scars would remain and the weakened ankle would produce a slight limp and occasional trouble in later adventures.
After the war, his parents sent him to college and then to law school. It was during this academic period of inaction, and apparent boredom, that he is approached by a man named Howard Shale to work as an agent of the CIA.
Gall worked for the Agency as a standard counter-intelligence operative for over a decade until he was forced out for arguing against the Bay of Pigs operation. Joe's words of warning fell on ears of those not only deaf to nay-saying but also vengeful against any detractors. When the operation actually failed miserably, those same people had no use for an 'I-told-you-so' so Joe Gall was forced out and not even his mentor, Shale, could help. Shale died in a plane crash in Vietnam shortly thereafter, and Joe Gall retired to the hills of the Ozarks with considerable bitterness towards the Agency.
Joe would be brought out of retirement by Shale's successor, Carl Wiley and it from this point on, where the novels commence, he works as a contract agent only.
When not on assignment, Joe retires to his home near 'Herald Springs, Arkansas'. His estate consists of five acres of land on a crest of a hill; his house was a 'huge clapboard castle with stained-glass windows and gingerbread turrets'. Behind his house was a Japanese garden complete with bonsai trees and an ice-cold natural pool fed by a large waterfall. Crossing the pool was a foot bridge and path leading up to and behind the waterfall to a deep cavern in which he had built a sauna. There is little doubt from his narratives that the house is his refuge.
In the recounting of the Bay of Pigs fiasco, Philip Atlee (nee James Atlee Philips) has his character angry over the Cuban disaster and uses it as the focal point for the changing of Gall's life and the creation of the 'Nullifier' vocation. He also spends considerable amounts of time commenting on the lack of intelligence in the Intelligence field.
This is of considerable note since the author's brother, David Atlee Philips, would take a major role in the planning of the real Bay of Pigs invasion while working for the CIA. David Philips helped collect the actual Cuban exiles who would eventually die or be captured and he set up numerous radio stations to spread false stories and heighten tension in Cuba prior to the landing, much as had been done successfully in 1954 against Guatemala.
David Philips was also the author of the plan to take American planes, paint them in Cuban colors, and give them to Cuban pilots who would strafe the Cuban airfields and then land in Florida claiming to be refugees from the Cuban Air Force. This story, a total fabrication, was repeated by Adlai Stevenson on the floor of the United Nations and led to considerable embarrassment for Stevenson and the Kennedy administration.
It is curious that David Philips' brother, James, would use the debacle as a major event in his creation's life when the book would be published less than two years later.
Note: The Burmese adventures of Joe Gall written about in the prequel, Pagoda, was used as the basis for the similarly named episode of CBS's Studio One In Hollywood in 1952, starring John Forsythe as the lead.