Mac McCorkle runs a bar and helps out his partner, who is a agent with the CIA.
When McCorkle took his life savings and began to open a small pub in Bonn, Germany, after being discharged from the army, he wasn't looking for a partner. That didn't stop Mike Padillo from dropping in, handing him a check for half the value of the place, and telling Mac he could either accept the offer or see the opening delayed forever in red tape.
Knowing he really had no choice, McCorkle accepted gracefully, albeit unhappily. To his credit, Padillo, forced by his own superiors to make the extortion, had the decency to be embarrassed.
So began the partnership between the two men, one that would quickly turn into a life-long friendship. Mike Padillo worked for the government (probably the CIA). When not on assignment, he helped run the bar, which grew over the years in success and made both a considerable amount of money. But every couple of months, he would show up, tell McCorkle he'd be gone for a while, and a week or a month would go by with him gone.
Such was the basis for the series which probably was never meant to be one. The ending of the first book made it pretty clear that was it. Then the book won for Mr. Thomas an Edgar for the best first novel of 1966. I'm sure that's when the publishers began to demand a sequel.
The sequel came the next year but this time Mr. Thomas apparently withstood the pressure for more and used his incredible talent on other ideas. Six books, including three in a different non-spy series followed before the pair of McCorkle and Padillo were heard from again. And then it would be 19 years more before the last in the series was written.
Through the years, the two unwavering qualities of this series remained the close friendship between McCorkle and Padillo and the terrific writing skills of Ross Thomas.