It’s easy to suppose that Patrick McGoohan’s John Drake from Danger Man is the same man as #6 from The Prisoner. Both are resourceful spies, ruthless but with a core of integrity, and of course with McGoohan’s sometimes bizarre but wonderful personal tics. But the most fun thing about such speculation is the occasional flash of the future prisoner in certain episodes of Danger Man. Oh, I know there probably wasn’t any grand intentional scheme that tied them together, but there are episodes of Danger Man where Drake begins to become dissatisfied with his masters. And there’s even one about a sort of proto-village. It transitions into the Prisoner rather nicely. Also, Drake often says “be seeing you”.
Probably the first episode in which Drake clashes with his masters is Whatever Happened to George Foster, in which Drake learns that a wealthy British lord is subverting the government of a small country for his own ends. The lord manages to influence Drake’s own boss (and his boss’s boss’s boss, the foreign secretary) to have Drake removed from the case, but Drake continues on his own and ultimately stops the lord by uncovering enough dirt on him to blackmail him.
The hypothetical resignation almost could have come about as a result of It’s Up to the Lady (though this theory is really dismantled by the fact that the episode is from the first season), in which Drake is called upon to persuade a defecting Englishman to return home. (spoilers) Drake manages it by persuading the man’s wife to change his mind, and he seals the deal on a promise that the man won’t be prosecuted on his return home — a promise made to him by his own boss. However, when they return, the man is immediately arrested. Drake seethes at his boss in vain, and the disappointed wife simply turns her back on him and walks away.
One fun Prisoner-esque episode is Colony Three, in which Drake finds himself (spoilers) at a Russian spy-training facility in the middle of Siberia that is a perfect model of an English town, complete with English defectors who are forced to play along. It’s very much a proto-Village, even down to the forced frivolity and undercurrent of menace. The other episode is The Ubiquitous Mr. Lovegrove in which Drake has a variety of very weird adventures that involve odd camera angles and sinister music. It turns out (spoilers) that Drake has gotten bonked on the head in a road accident and the whole thing has been imagined, incorporating the doctor and others standing around him, Wizard-of-Oz-stylee. It’s weird in a way that would become familiar in The Prisoner.