As convoluted as a good spy story. Like its protagonist John Drake, The Danger Man series had many identities, beginning as a half-hour British spy show starring an American-accented Patrick McGoohan, then going on a brief hiatus before being revived as an hour-long drama (known as Secret Agent stateside) with a more Bond-like McGoohan now sporting a British accent and a slight smugness around the edges.
After watching a very serious McGoohan dash his way through the 24-minute dramas in his phony but engaging clipped accent, the longer more traditionally-paced episodes felt less like a discovery. But allowing for some dated pacing and less appealing 1960s conventions (were there really no ethnic actors anywhere to play their own nationalities?), the series is unmatched in its field. A big part of this is McGoohan of course, who is almost magically engaging as a Cold War-era warrior. Very dry in character, they have the literary conventions that obviously still influenced the medium, before the baby boomer demographics gave us shite like Mod Squad or Starsky & Hutch.
The gold standard for episodic spy dramas. Enduring.