Charles Jenkins novels

"Former CIA case officer Charles Jenkins is a man at a crossroads: in his early sixties, he has a family, a new baby on the way, and a security consulting business on the brink of bankruptcy. Then his former bureau chief shows up at his house with a risky new assignment: travel undercover to Moscow and locate a Russian agent believed to be killing members of a clandestine US spy cell known as the seven sisters. Desperate for money, Jenkins agrees...

After a harrowing escape from Russian agents on his last mission, Charles Jenkins thinks he's finally done with the spy game. But then the final two of the seven sisters--American assets who have been deep undercover in Russia for decades--cut off all communication with their handlers. Are they in hiding after detecting surveillance? Or have they turned and become double agents? It's Jenkins's duty to find out, but he's been added to a Russian kill...