Well, the star of this was Patrick McGoohan, who went on to fame in (and in fact, quit the Secret Agent series to do) "The Prisoner."

McGoohan was two shows into a new season of SECRET AGENT when he decided that he'd had enough. Fearful of losing him, they asked what he'd like to do instead and THE PRISONER was the result. There was haggling over how many episodes to shoot; McGoohan wanted to do only six or seven while the network wanted a full season. They finally settled on the 17 that were filmed. Those two episodes of SA were edited together and became the ersatz movie KOROSHI.

THE PRISONER played as a summer series on CBS in the U.S. and was repeated the following summer. After that it went into syndication.

If you're not familiar with "The Prisoner," McGoohan is some sort of a secret agent who quits his job, gets gassed into unconsciousness and kidnapped shortly thereafter, and wakes up in a village where nobody has a name, just a number. He spends the entire series trying to escape, only to be thwarted by the village officials, and a mysterious balloon that chases him around and envelops him if he gets too far away. I have, and have watched, them all. It's one of the most unique series in TV history, IMO.

I rate it the greatest TV show ever. It works on many different levels and always has something contemporary to say. The mysterious balloon was named "Rover."

"Danger Man" was pretty much an English broadcasting show, which evolved into "Secret Agent." American audiences saw "Secret Agent" first, if I have it right. Pop singer Johnny Rivers did a version of "Secret Agent Man," which was the theme song. If it matters to you, the shows are in black and white, which for me is a plus, but I'm old....

The Johnny Rivers song was only for the U.S. The harpsichord theme by Edwin Astley, which usually followed the main title, was the actual theme music for the show.

I have several episodes of "Danger Man," on DVD, but have only watched a few. They're pretty good. McGoohan is a very suave, but not a "look at me, I'm a hunk," character that is easy to hate. In fact, his adventures have very little to do with the amour, but are instead dramatic encounters with political nasties and crooks.

Notice that he never uses a gun nor kisses a girl. His "no kissing" policy is what supposedly lost him the role of James Bond.

Besides those few novels that were published there was also a graphic novel set 25 years later.