Jack Hunter is a part-time American spy.
Well, he will be. When we first meet him, he is a swashbuckler. There are not that many people who can say with any degree of honesty that they are a swashbuckler but Hunter can. "Action Jack", that's what he is called by the tens of thousands of people who have enjoyed him swashbuckling around the world.
The introduction to his first recorded adventure puts it well. "Everyone liked Jack Hunter. The whole world knew him—or thought they did. His movies were marvels of light-hearted heroics, quick wit, and charm, each almost perfect portraits of the dashing star himself." It would go on, though, and mention "scandalous shenanigans" that he was often involved in. It would also mention, finally, that in that first hair-raising escapade, "Jack revealed himself to be something quite different from the swashbuckler he had been pretending to be in pictures. Everything changed for the star at that point, never to be the same again".
So, now comes the question of how a movie-star who appears on celluloid as a larger-than-life hero but who is really a very normal, understandably skittish human being becomes a part-time spy. It certainly is not in the pages of that first book where staying alive in the Amazon pursued by head-hunters occupies all his attention. It is, rather, later when the world has heard how awesome he was there (he wasn't) and he has learned how much more he would like himself to be that he would make his foray into the cloak and dagger world.
Luckily for the safety of his backside, the same fantastic woman, Maxine 'Max' Daniels, Hollywood animal trainer and real hero of the day, who saved the day on the South American adventure, will be around to show Hunter the ropes.