Kent Steele is an agent with the CIA.
He has been one for quite a few years and was rated as one of their very best for most of that time, a man who has performed impossible tasks in a wide variety of spaces around the globe.
Reid Lawson is a professor of European History at Columbia University, a widow who greatly misses his wife of many years who died some time back from a brain aneurysm. Despite the heartache, he manages to raise his two loving teenage daughters, Maya and Sara. He has been a college instructor for most of his adult life, starting shortly after he himself graduated and rising through the ranks to be the respected 38-year-old academician that he is.
The problem is that Reid Lawson is Kent Steele. He just did not remember that he was. But, of course, he could not have been standing in front of students each day as his memories tell him he was if he was also busting in doors to take out terrorist cells. Right?
As Lawson slowly and painfully realizes that much of his life was not real and deals with memories conflicting with other memories, bad things start to happen that he is the perfect man to handle. The trouble becomes that to deal with all of these matters is likely going to lose for him the things most precious to him.
Lawson/Steele is an extremely dangerous man who, even though he is in his late 30's or early 40's, can still move with impressive speed and agility which is vital because as he regains those memories, he remembers and realizes there are a lot of people who would love to get their hands on the operative codenamed 'Agent Zero'. And if they cannot snatch him, shooting him or blowing him up is almost as good.
As one adversary says to him, "Agent Zero. Many of us know you as Kent Steele, but all know of Agent Zero. Like a legend—an urban myth. A name that inspires fear in the most stalwart." A bit flowery, perhaps, but it definitely fits.