Randall McCarey is an agent with Bureau-X.
First a small amount about that department before we get into the confusion that is Randall McCarey.
In the first page of the first recorded adventure, we are told by the narrator that Bureau-X, which is often abbreviated Bu-X, is in fact properly known as the International Intelligence Agency. An odd name for it since it appears to be totally belonging to the American government. One of the incarnations of McCarey (more later) states that Bureau-x is "something like an international counter-espionage outfit, but not quite. It isn't quite because it's outside all law and all restrictions and all supervision. Some people, like the President, for instance, can suggest; no one in any civilian capacity gives any orders. Yet, contraty to all logic, Bu-X isn't military either, in any accepted sense". Clear now?
On to the mysterious Randall McCarey.
There are three recorded adventures attributed to that man but in the first one, he does not get mentioned at all. Nary a word about anyone named Randall or McCarey.
That first adventure deals with a second-generation Russian-American named Alexis Ivanovich Bodine, born in Brooklyn in 1921 and raised there to attend Columbia University to earn an M.A. and buy a ticket to work on an archaeological dig in Egypt. Then his father passed away, Pearl Harbor happened, and his life changed. He joined the US Navy, got a commission some time later, and then was moved into Naval Intelligence where he was sent behind enemy lines in the Balkans. Naturally his primary role would have been helping fight the Nazis but he nevertheless must have had run-ins with the Soviets because he "killed, for one reason or another, some eleven N.K.V.D. men ... and I was ... a favorite quarry of the Russian secret police". Bodine would, as the first book tells us, go on to become an even bigger enemy of the Soviets.
The second adventure tells about the intrepid but rather mouthy Jeff English, an agent with Bureau-X as long as he has been an adult and since he has is in his mid-30s at least, that is a lot of missions and a lot of chances to make people angry with him. His latest assignment is to take the role of a security officer at an atomic research facility and while there to find what scientist is leaking secrets to the Reds and eliminate him. The identity of the role he is given to play is that of U.S. Army Captain Randall McCarey. From the intensive training session he is given on McCarey's history, it is apparent that McCarey was an actual person because it was vital English know it well. It was also very obvious that McCarey, whoever he was and wherever he was, was a prime example of a jerk. Loud-mouthed, bossy, demanding, and quite unfriendly except with the ladies, whom he would always love and leave without remorse.
The third adventure brings us first to a bank in Michigan where a middle-aged man named Randall McCarey is the manager and has been for a while. McCarey, whose family has owned the bank for a couple of generations, is not looking for any change in his life but is also a tad on the bored side so when the offer for a drastic change comes, he hardly hesitates at all. That change comes in the form of his former boss at Bureau-X, back in the day when he was an agent with them - back when his real name was Alexis Bodine, second-generation Russian-American.
So who is the real Randall McCarey? The first and third adventures are clearly about Alexis Bodine but when did he become Randall McCarey, a chap who has had a familial connection to a bank apparently all his life. And what became of Jeff English?
In the style of the game show To Tell The Truth, three men sit before you and eventually one is supposed to stand and admit the truth. In the case of McCarey, I would not have a clue who would rise.