Hush Hush by Stuart Woods

 This "Stone Barrington" book had more plot--and less sex (well, fewer sexual partners)-- than usual. Stone's previous contact with the Russian mob, which didn't end well for the mob, has come back to bite him in the butt. 

Jim Rawlins from a previous plot pops up and plays as a major role. And there's a cute computer expert for the CIA named Rocky who plays a major role. But otherwise the story features a lot of the regulars: Dino and Viv, Lance  Cabot, Holly Barker, and Dame Felicity--as Stone (and Rocky) travel from NYC to London to Maine trying to escape a crazy hitman fueled by revenge.