Atticus Wolfe is an agent with MI6.
That is the MI6 of today, it is important to say. An MI6 where having agents of color is not a rarity. He is also, eventually, going to be an agent of this other MI6 but it will take some convincing. The other MI6 you ask? Well it is the one that existed in 1963 which is, by my math, technically the same organization but sixty years younger than the one that Wolfe is an agent with.
In the one he is familiar with, he is one of their top operatives though there are many who would like to stay mum about it (apparently there is not much use in arguing against it because he really is that good). He is also known to be a lone wolf who more often than not will go it alone so he could do things his own way. That will be sort of a good thing when he confronts a strange type of terrorist at the very beginning of the first recorded adventure and the man sets the device off and Wolfe awakens in a hospital with considerable injuries and eventually an astonishing realization.
The nurse treating him is dressed as Wolfe thinks is cosplay with her "bouffant hair, crisp white uniform, equally pallid shoes and a nurse's cap, like something out of The Flying Nun". The doctor finishing his examination is joyously puffing on a cigarette and pooh-poohing the "recent" report outline the dangers of nicotine. The only phone available for his use is the pay phone down the hall. And the newspaper there to read is one that went out of business a couple decades before Wolfe was born; the headline of which Assassinated! Kennedy shot dead in car!", date November 23, 1963.
The bomb that exploded around the terrorist and Wolfe did not blow them up so much as blew them back - back to the 60s where the terrorist feels was the best time in which to begin his scheme of changing how "the French and the English" would "make a mess out of the Middle East" through their meddling.
How it works is not something Wolfe would really have a chance of understanding but it did work and now Wolfe is back in that period, armed with a mission to somehow keep the terrorist from changing the future - Wolfe's past.
Wolfe is a black man now forced to operate in an England where people of color were only just beginning to be heard and seen. He is an employee of a government agency which was known to exist by just about everyone but which had not yet admitted its own existence. And he has to deal with the fact that as a man from 2024, he is very much a fish out of water, or in his case, a man of a different time.