Steven 'Steve' McQuinn is an American diplomatic courier.
Working for the U.S. State Department, the job of the courier is summed up quite nicely in the opening blurb told at the start of each of the televised adventures: "One of the vital functions of the United States Government is to establish and maintain diplomatic relations with other countries. In every friendly and civilized nation in the world there is an American embassy or legation. Whether it is Paris or Cairo, Shanghai or any other remote outpost, the most reliable and confidential means of communication is the Courier service.
Armed only with his passport, the courier, like a global postman delivers the top secret dispatches of our Government."
Working in this capacity, McQuinn is as likely to be sent to capital in Europe as he is to one in Africa or Asia. In fact, in the 39 adventures we have of him, he hits some major city in each of the inhabited continents. No city was repeated in this sequence. Europe was by far the most 'popular' destination with 13 different countries hit. Asia was traveled to a fair number of times with the Americas, Australia, and Africa getting a few visits.
McQuinn worked alone and, as the blurb above indicated, he did so without being armed except for his fists and his diplomacy; with regards the former, he did not resort to physical violence that often because he was pretty good at using his brain and his wit and his tact.
McQuinn, approximately 45 years old during the time of these stories, is extremely urbane, sophisticated, well-bred and well-spoken, and has a tremendously effusive and ready smile that can light up a room or diffuse a tense situation. At the same time, however, that smile can disappear instantly and his face take on a far sterner mein when trouble persists. His ability to turn to a man of action is highly impressive and not a little worrisome.
If all that McQuinn became involved in during his constant traveling around the globe was, as the opening sequence showed, having a diplomatic pouch handcuffed to his wrist as he either headed out to some embassy or returned to D.C., interest in his movements would have waned almost immediately. Travelogues can be interesting but lacking in excitement and watching him woo beautiful women over and over would have been voyeuristic in nature and prone to envy. What made the McQuinn stories so enjoyable were the "extracurricular" activities this courier got involved in that definitely did not fall within the normal job expectations.
There are a few adventures in which unpleasant things happen during the 'normal' execution of his duties, such as combating those who want to steal what he is transporting or getting it back once it has been stolen (South Vietnam, Baja, India, Ireland).
Then there are the times he is called upon to rescue people from kidnappers, or bandits, or other types of criminals (Spain, Burma, Brazil, Italy, Greece, Malaysia).
Several times he is asked to give aid to refugees fleeing totalitarian nations (Tangiers, Switzerland, Czechoslavakia).
More than a few times he is involved in saving old friends either from nasty people out to do them harm or from their own foibles (France, Cuba, Italy) or catching the killers of those unfortunate chums (Iran, Macao).
There are many instances of McQuinn doing what would be considered normal spycraft not in the courier handbook (France, Turkey, Syria, England, Yugoslavia, United States, Australia, Monaco, Morocco) or handling police work for which he has no badge (Peru, Philippines, Austria, Scotland, Antigua, South Africa, Israel).
The remaining adventures tend to really defy labelling but sound like a lot of fun to watch as well.
Regarding always meeting new women in each place he visited, McQuinn commented that he felt like a sailor too often, lamenting, "For once, I'd like to say hello to the same girl I said goodbye to the last trip."