Drummond Clark is a former agent with the CIA.
For nearly thirty years, Clark had been one of the top operatives the Agency had, operating throughout the world handling a wide assortment of missions with tenacity and with intelligence. He had attained a tremendous reputation as a man who got the job done, and done right, and who never caused trouble except to the bad guys.
Early in his career he was often teamed up with the same female agent, usually pretending to be husband and wife and as seems inevitable, they frequently consummated their faux nuptials. After a couple years, son Charlie was conceived. The couple got married and tried to settle down while still working as agents. The real marriage did not work out as well as the fake one and after a few years, she “died”, leaving just Drummond and Charlie.
The relationship between father and son was often a chilly one. There was definitely love between them but Drummond was often gone on assignment and when he was home, he really did not know how to connect with his son. For most of Charlie's upbringing, they were polite with each other; there were no real problems but no real connection, either.
To Charlie, his dad was a boring, anal-retentive father whose day job was traveling the country selling appliances for a third-rate manufacturer. Nothing in the first 30 years of Charlie's life ever gave him reason to doubt these facts.
When Drummond passed 60, his mental health took a sudden downturn as he began to suffer from premature Alzheimer's and the prognosis was not good. He retired from the Agency, or the appliance business, and began needing special care. Charlie, who had long since moved out, helped on occasion but Charlie had his own problems, having never seen a horse race he did not want to bet on and finding himself more than twenty grand in the hock to a loan-shark.
As the series opens, Charlie is assisting him father to visit a social worker when some one tries to kill them. Charlie thinks it is the loan-shark out for blood. A suddenly lucid Drummond knows the truth. Someone in the Agency is afraid of what a babbling Drummond might say to the wrong people and a dead Drummond would not have that problem.
So the situation becomes that a highly experienced agent suffering from acute memory lapses is on the run with an intelligent but untrained man trying to elude an incredibly powerful world-wide intelligence agency. Charlie knows the odds are not with them.