All the Old Knives - Olen Steinhauer

Celia used to lie for a living. Henry still does. Can they ever trust each other? Six years ago, Henry and Celia were lovers and colleagues, working for the CIA station in Vienna, until terrorists hijacked a plane at the airport. A rescue attempt, staged from the inside, went terribly wrong. Everyone on board was killed. That night has continued to haunt all of those involved; for Henry and Celia, it brought to an end their relationship. Celia decided she'd had enough; she left the agency, married and had children, and is now living an ordinary life in the Californian suburbs. Henry is still a CIA analyst, and has travelled to the US to see her one more time, to relive the past, maybe, or to put it behind him once and for all. But neither of them can forget that question: had their agent been compromised, and how? And each of them also wonders what role their lunch companion might have played in the way things unfolded...