Dan Dailey is an agent with the DIA.
It was in the mid 1960s that Dailey, after attending the University of Oregon, chose to enter the military, picking the U.S. Army. His impressive skills with foreign languages took him into the Intelligence section and, after some time amassing an "exemplary" record, he was noticed by the Defense Intelligence Agency and offered a position. He obviously took it.
After a couple of years of action, he appealed to an old college friend, James "Bull" Bulliard, to leave his failing business and join him in the excitement and danger that was becoming a regular job description. Bull agreed and while the two do not always work together, they do enough to consider themselves partners.
In the DIA, their immediate supervisor is Colonel Riley, a man who has learned over the couple of years the two men have worked for him that it is best to point these two members of the "Have Balls - Will Travel" team in the direction they need to go and then just let them handle things.
As it says in one of the passages, "take a couple of street-wise Army spooks, add a generous dollop of disrespect for authority, and you had a Special Ops team capable of resolving issues literally in the dark allies of international intrigue."
Dailey is of slightly above average height and is in terrific physical condition. Few might notice that, however, when Bull is nearby because Bull is a "huge" figure who dominates a room. That is fine with Dailey because it is his brain that really dominates.
As the series begins, Dan Dailey has recently lost his fiancée to breast cancer and still has nightmares brought on by the grief. The action helps take his mind off his sorrow.