Simon Riske is a freelance agent.
He has been at times called an industrial spy but he does do the occasional (okay, more than occasion) job for MI5 and MI6 so his contacts in the intelligence community of Europe is impressive.
When we meet him, he is an operative. He was not one for quite a while, having had a successful career going as a crook.
We are told in a blurb for the first recorded adventure that it was around Monaco that Riske "was once a thrill-seeking thief himself, robbing armored trucks and leading police on dangerous car chases across the Côte d'Azur, until he was double-crossed, served his time, and graduated as an investment genius from the Sorbonne."
We also learn that he "lives a mostly quiet life above his auto garage in central London. He is hired to perform the odd job for a bank, an insurance company, or the British Secret Service, when he isn't expertly stealing a million-dollar watch off the wrist of a crooked Russian oligarch." There is also a statement that "Simon has maintained his quiet life by avoiding big, messy jobs" though considering the adventures we follow him on, that avoidance is questionable.
The comment that I enjoyed most about Riske, prior to the joy of actually reading the stories about him, was that "Riske is a man who solves problems, the bigger and 'riskier' the better. From the baccarat tables of Europe's finest casinos to the superyachts moored in Monaco's Port Hercule to a secluded chalet deep in the Swiss Alps, Riske will do what he does best: get in over his head, throw himself into danger, and find a way to outthink and outmaneuver villains of every stripe."
Riske is described early on as "a compact man, an American, markedly fit in a bespoke navy suit...His hair was dark and thick, receding violently at the temples, and cut to the nub with a number two razor. He had his father's dark complexion and brooding good looks and his mother's beryl-green eyes. People mistook him for a European - Italian, Slavic, something Mediterranean. His nose was too bold, too chiseled. His chin, too strong. Take off the suit, add a day's stubble, and he'd fit in hooking bales of Egyptian cotton across a dock in Naples."
His day job is that of repairing and restoring super-expensive automobiles. If you bang up your Lamborghini or Ferrari, his shop is a good place to take it. It will cost you but the results will be worth it. He really does enjoy getting his hands dirty by making these high-performance vehicles clean again.
But nothing excites him like the challenge of being asked to help when Person A has something very valuable stolen by Person B and needs it back without anyone learning of the theft. Sometimes it is MI5/6 upset about someone absconding with some secret papers. Sometimes it is a very rich and powerful corporate executive who learns that an underling has made off with a hush-hush ledger. The greater the challenge, the more Riske relishes the, well, risk.
And because he was, in his early adult years a daring hood who went to prison without grassing on his mates, he has a fair number of valuable contacts in the underworld. Some of them owe him a favor or two. Some would like to hand him a shiv the wrong way. All of them are valuable one way or another.
Then there was the decade or so he spent in the high finance world of hedge funds and deal making which has left him with a ton of wealthy and wanna-be-wealthy contacts who know that helping him with an answer here and suggestion there will pay off in the long run.
And because his current business has him fixing up the expensive playthings of the rich and famous, lots of doors get open for him from that. Of course, considering his distance criminal past, if a door is not opened willingly, he knows how to jimmy a window when called for.