Nathan Muir, Russel Aiken, and Tom Bishop are agents with the CIA.
These are the three main players in the Aiken Trilogy also referred to as Spy Game. Of course, there is yet another incredible adventure by that very name included in that mixture without which the other three actually listed in the Trilogy would be, well, still incredibly good and well worth the reading but nowhere near as enjoyable. Without a doubt, the entire series is best savored when including this fourth (actually holding the second position in the quartet).
The series displays these individuals as making up a fascinating triumvirate. We have an old and some say anachronistic veteran of the spy game, a young-ish newcomer to the business, and someone in the middle who would not mind being thought of as either of the others but knowing he never will be.
Nathan Muir is without any doubt the most experienced and capable of the three. When we first meet him he is quickly approaching his retirement, forced perhaps by both the system and his own growing lethargy). As we follow him in the next few weeks we also learn that while there are still some who remember just how terrific and skilled he was at his job, his time was during the Cold War when the game was played by individuals in field one-on-one with citizens of foreign lands in their playgrounds and yet he was good enough to make the rules match his agenda.
Now, though, as we meet him, there is a whole new generation wanting the old guard to just go away and let the new guys play with their technologically impressive spy satellites and powerful decoding computers all within the very, very safe walls at Langley - if one ignored the constant in-fighting and back-stabbing that took place there. Muir is well aware that many want his head as a trophy much as the aging gunfighter in the Wild West had to constantly face his share of fast-gun artists wanting a name without paying the normal price.
Tom Bishop was a highly skilled and slightly off-kilter Marine Corps scout and sniper in 1975 when he is noticed by Muir and pegged as a man whose talents lay far beyond his ability with a long-range rifle. Muir would not long after begin the process of recruiting Bishop into the Agency but also teach him and become his mentor. Bishop will not be the first that Muir has graced with his tutelage but he will be the become by far the best.
Bishop is a very handsome, physically fit man who had a winning ready smile and a charm that seemed boundless as well as a terrific eye for talent to bring into the reach of the Agency as assets out in the field. He could wine and dine as was often the case but he could also research and study and find what it was the the prospect really wanted out of a covert relationship. Bishop's biggest weakness, and some would say strength, was that he cared a great deal more for his 'people' than either Muir or Aiken was capable of.
Finally, there is Russell Aiken, a lawyer employed by the Agency who was once thought to be Muir's next wunderkind but who has since lost the look of appreciation and pride that he once thought he saw in Muir's eyes, if he ever really did. Our introduction to Aiken comes when another aged operative is blown up in his boat and Aiken is sent to that fallen agent's own long ago trainee, Muir. The powers that be (or want to be) in the CIA would like as much of the blame put on Muir's shoulders so as to force him out immediately and that meant Aiken had to venture into Muir's lair and much like invading a bear's den is never a good idea, that is the case with Aiken visiting Muir.
As circumstances unfold in the four-adventure set, we find Aiken falling precipitously and then reaching a level of stable but largely insignificant existence at headquarters and then, throw no act on his part being pushed into his own version of the limelight in the last adventure.