A dinner in Carmel-by-the-Sea dominates Olen Steinhauer’s All the Old Knives” — a reunion of Henry and Celia , old CIA colleagues and former lovers, one of whom still carries a torch. Henry has e-mailed that he’s “going to be in your neck of the woods. . . . Some company thing in Santa Cruz,” and Celia, retired and living in Carmel with her husband and two kids, replies that she has “been living in a bubble of my own construction for far too long; it’s time to let in some fresh air.”

Both messages prove disingenuous, and not just because of the possibility for rekindled romance. Henry’s “company” business (he’s still with the CIA) concerns Celia — the next person he needs to interview about a terrorist attack from their shared time in Vienna. Five years before, hijackers took charge of a plane at Flughafen airport, moved the children to the front of the aircraft as a human shield, demanded a hostage exchange, vowed not to negotiate — then didn’t, leaving 120 dead. An informant at Guantanamo Bay has suggested that the agency’s response was compromised by a traitor within its ranks, and Henry has been tasked with investigating.

Could it be Celia? Or someone she’s shielding? The stakes are high. As his boss tells Henry, “We can’t afford the embarrassment of a prosecution.” If guilt can be proven, the culprit will have to be eliminated. But as Henry reflects late in the story, “In each man’s life there are only a few women who can turn him inside out, who can cripple him with a smile” — and Celia’s the one for him. But what about her agenda for the evening? As she tells Henry with a raised glass and that crippling smile, “Welcome to California. Don’t take any of us at face value.”

“All the Old Knives” is a splendid tour de force. While some spy novels are globe-trotting and action-packed, this one centers on a single meal — but with just as hearty a helping of suspense. Without neglecting the turmoil of the geopolitical landscape, the novel focuses more intensely on the equally treacherous landscapes of the human heart. The restaurant where they meet is called Rendez-vous, with a hyphen (“no snide comments, please” says Celia ); the conversation veers uneasily between flirtation and interrogation; and the stories of Henry and Celia’s old love affair prove ultimately inextricable from their professional pasts. With Celia having moved up the ranks from Dublin to Vienna and Henry “limping out of Moscow” in the wake of the Dubrovka Theater hostage crisis, the two of them entered fitfully into a relationship burdened by costs of the profession: a life built around secrecy, deceit and distrust. “That’s spooks for you,” says Celia’s boss. “Always thinking of the angles. Protecting themselves to the point of exclusion. I’m trying to remember one example of two field agents who ended up in a successful relationship. . . . I can’t.”

The Flughafen airport hostage crisis continues to extract professional and personal tolls. Even after escaping to paradise, Celia has nightmares in which her own kids perish in the terrorists’ hands. Awkward and conflicted, Henry proves driven, relentless about his mission. After their dinner, he knows it will “take more than a pretty beach to scrub my soul clean.” A delicate balance of conflicting, then conflating, perspectives determines how the truth about Flughafen unfolds.

While it might seem an odd comparison for an espionage novel, the mystery here works with the dexterity and precision of Agatha Christie’s best — the answer to whodunit and whydunit being both surprising and ultimately inevitable because the clues are in plain sight.

But the puzzle is just one aspect of a story that’s freighted with considerable emotional and moral weight. If the ending is crisp with irony (like one of those old Spy vs. Spy cartoons from Mad magazine, but elevated to elegant purity), it’s also hauntingly ambiguous, both morally and dramatically. As much as Steinhauer might be exploring how a career in espionage can thwart personal relationships, he’s also plumbing how the personal influences the professional — the role of the human factor, to borrow from a title by Graham Greene, an author to whom Steinhauer has frequently been compared.

“A man in love goes through the world like an anarchist, carrying a time bomb,” wrote Greene in that novel — words that echo here, as Steinhauer proves that love offers multiple opportunities for detonation.

Taylor, who teaches at George Mason University, frequently writes reviews for Book World.

ALL THE OLD KNIVES

By Olen Steinhauer

Minotaur. 294 pp. $23.99