Marcus Tregay and Sophie Lefévre are security consultants.
Together they run a very successful business out of Switzerland named Myrmidon SA, a business that Lefévre's father had started and which she had taken over on his death. She had proven to be as good as he in the management and its reputation had stayed strong. Tregay came along sometime later and, after falling in love with Lefévre and needing something to occupy his time, decided to join her in business as well as personally. His pride and her business acumen, though, meant he had to buy his partnership.
Lefévre sat behind a desk and ran the company, sending her employees around the globe when contracts came in and making sure they were outfitted enough to succeed and survive. This might make some think she was a paper-pusher and not capable of field work. This would be a very costly error in judgment because she made sure she knew as much as possible about the actual work and though she might not have as much real experience as some of her operatives, or of Tregay, she proves over and over she is a quick learner.
Tregay, on the other hand, is new when first we meet them to the security business but not to the type of work they would routinely contract. He had been in the British Royal Marines and then as a long serving member of the elite Special Boat Squadron. In addition, he had found himself, usually without pleasure, being seconded to the SIS and sometimes by extension to the CIA. This left him with sour tastes in his mouth but a tremendous amount of experience dealing with clandestine organizations.
Together they make a very impressive and lethal couple that does not look for trouble on their own but which find it nevertheless.