Ed Noon is an agent for the President.
Noon was first operating as a private investigator in 1953, apparently hanging it in 1989, making a career in the gumshoe business lasting 36 years at least. During that time he did a bit of everything that a PI would be expected to get involved in - beautiful women in distress, really really bad guys, thugs with guns, luscious femme fatales, etc. He was both hard-boiled and hard-loving and he was moderately popular to the reading public.
Along the way, he took on an additional role besides private detective when he is literally shanghaied and brought to the White House where the President asks him for help. The President indicated that he was chosen because of the work he had done on the government's behalf in the matter of the "alarm clock". Noon isn't one to say no to an interesting case and he agrees.
From then on, the series fluctuates between Private Investigator and Spy adventures. It also shimied back and forth with publishers with Signet releasing paperbacks billed as "Agent to Mr. President" while Curtis came out with a mixture of both PI and Spy without differenciating. The crossovers were smooth, however, as Noon remained in New York working out of his office he called the "mouse auditorium".
Ed Noon is an old hand at the detective business as well as dealing with trouble. He got his first taste of danger while serving in WWII in Europe, rising to the rank of Sargeant. Upon his discharge, he sort of fell into the investigation business and sort of fell into having to fight frequently to stay alive.
Ed is quick with his brain, fast with his fist, and accurate with his favored .45 carried in a shoulder holster.
Listed below are all the published adventures about Ed Noon. In front of their plot description is either [PI] showing a private eye story or a [SPY] showing a spy adventure. One is a [?] indicating uncertainty and one has a [BOTH] showing that there are elements of both. Of the 33 books, more are PI books but with at least 13 books with Noon as a spy, he more than qualifies for membership to the Spy Guys and Gals club.
Notes: (taken from the excellent website Thrilling Detective)
1: There were several short stories written about Ed Noon and published by various magazines, mainly the Mike Shayne Mystery Magazine.
2: In the mid-50's there was a 13-episode radio serial called The Windup starring Chester Morris as Noon.
3: In 1999, the last, unpublished Noon adventure, Since Noon Yesterday was filmed and released as a 7-part webcast by the author's son, David Avallone.