DeMille, Nelson. John Corey novels.

After a showdown with the notorious Yemeni terrorist known as The Panther, life seems to be getting quieter for maverick Federal Agent John Corey. Professionally sidelined, away from his wife, and partnered up with a young, good-looking rookie named Tess, Corey is saddled with a dead-end job running easy surveillance on a group of Russian U.N. delegates in New York City. But then his subjects slip the net, Tess starts acting suspiciously, and an old, dangerous foe reappears. With Russia resurgent and a clear and present danger in his own back yard, suddenly Corey's life hits the fast lane once again