Hunter Blacke is an agent with an unnamed American agency.
The bureau is not necessarily ultra secret, at least not as Blacke talks about it. He just does not give any clues about its title or location other than it is American. He also does not let on how long he has been an operative but it seems like a fair amount of time because his position is secure enought that he can annoy his boss without worry.
As a cover for his real job, Blacke operates as a specialist in hotel reconstruction and renovation. He might work on other things, like restaurants and such, given the odd hint or comment but hotels, or resorts, are his mainstay and apparently he is quite good at it. He is also trained as a tour operator and expert in tourism which has to come easily since he travels the world already looking for places companies can build new facilities or ways to fix up sagging older places.
For his official job, he would go to a region and study it so he might give advice to whoever was hiring him how best to build a hotel, market it to become known, and how to learn who the good guys in the area were and who were the bad guys.
As he travels all over doing very legitimate work for legitimate companies, he can also take the time to handle assignments for his agency. His being an expert in fixing up damaged property comes in handy at the end of some of his missions because where he goes, bad things do to. "I was a shadow. Wherever I went chaos would follow," is how he put in once.
While he was trained in close combat as well as ways of extracting information from people, willingly or otherwise, when it came to doing his job, his attitude was to gather the intel anyway necessary and then "get the hell out of the circumstance" without leaving evidence he was there. His success rate had to be good to be constantly called for but he modestly remarks that he felt his skill levels were "adequate to the task".
One other thing beside travel and adventure that Blacke likes, and which he will spend a good deal of time talking about, is the food at the areas he visits. He adores trying new dishes and new beverages and then telling his opinion.