Victor Sebastian, codenamed Five Fingers, is an agent with American Counter-Espionage.
"This is the dossier of an American; his name, Victor Sebastian. Only one out of every three people in his line of work survives. His occupation - counter-espionage for the government of the United States. I know these fact because I am Victor Sebastian. My codename is 'Five Fingers'."
With this introduction comes the Morse code for "5FINGERS" ( '..... ..-. .. -. --. . .-. ...' for those of you curious).
At the time of its premiere, a synopsis blurb released said that Sebastian was "America's top counter-intelligence agent, master of espionage and split-second action. In the shadowy world of international intrigue, he stalks and is stalked by his country's enemies in chilling undercover battles of a grim Cold War."
One of the episodes starts with Sebastian entering late at night into his office located at Room 2318 of an unspecified building, the door to those offices showing the company name of "Wembley and Sebastian, Ltd" with offices in Paris, New York, and London. As Sebastian, dressed in top coat with hat and gloves, turns on the light and sits at his desk, he tells us, "To the entertainment world on two continents, I am Victor Sebastian, theatrical agent. These are my offices. But the business I am about to conduct can never appear on the company's books. Not if I am about to survive. Because, as it happens, I am also another kind of agent; counter-espionage. My employer - the Unites States government. Although sometimes I pose as its enemy. My codename - 'Five Fingers'."
Sebastian's activities takes him all around Europe where his reputation as a theatrical booking agent is well established, making him at home in clubs and restaurants in all major cities. As the explanation above mentions, sometimes his real job is to ferret out intelligence from others while on occasion he appears to be a double agent in order to infiltrate an enemy operation.
When we first meet him he has but on person who knows his true occupation, that being his contact/handler known to us only as Robertson.
We also are able to meet the young gorgeous fashion model and would-be singing star, Simone Genet, who is clearly enamored with Sebastian but is unaware of his true vocation. She is, though, smart enough to start realizing there is more to Sebastian than he lets on.