Charles Cumming’s thrillers have been favorably compared to those of John le Carré and Len Deighton, and justly so. The three British authors sharply evoke a shadowy world of spies who can be heartlessly expedient and whose loyalties can spin like a demented compass.

"A Divided Spy," by Charles Cumming (St. Martin's)

But Cumming’s novels depart significantly in one respect from le Carré’s and Deighton’s, as his latest, “A Divided Spy,” makes clear. Purpose and caring temper protagonist Thomas Kell’s cynicism, lending him more warmth and sensitivity than le Carré’s and Deighton’s often embittered agents.

Troubled by a divorce, cut loose from MI6 after a scandal, the 46-year-old Kell seeks refuge in work. His opportunity arises when he learns from Harold Mowbray, also an ex-spy, that he spotted Alexander Minasian, the Russian agent who ordered the death of a woman Kell loved deeply (the killing occurs in Cumming’s previous Kell thriller, “A Colder War”). Mowbray says he saw Minasian at a resort in Egypt quarreling with a gay lover, Bernhard Riedle.

Kell sniffs opportunity: Minasian has a wife in Moscow, not a place where a closeted gay man wants to be outed. Kell reasons that a threat to expose the Russian’s secret life might successfully pressure the Russian to become a double agent, feeding Soviet secrets to MI6.

Playing Minasian this way offers Kell sweet revenge for the death of his lover. His plan is to film Minasian and Riedle having sex, and then to use the scene to blackmail Minasian. Kell’s former boss at MI6 tacitly approves the idea. You’ll “have what you need, Tom,” she says, “the head of John the Baptist.”

Kell goes after Minasian, his resolve to stay off booze and cigarettes faltering daily. He lands first in Brussels. Here he manipulates the aging Riedle’s emotional needs for young, fit Minasian, persuading Riedle to set up a reunion that will “lure him out of the shadows.”

Kell and Minasian eventually face off in London in a swift, taut scene that’s one of the best in the book. Stunned by what Kell knows about him, Minasian reflects on the seductive nature of British intelligence investigators: “In Moscow, they roughed you up and shot you. In London, they took you for oysters; only later did you find out you’d picked up the bill.”

Kell at first eyes Minasian as “a snake slipping out of his skin and into another.” He questions, in particular, whether Minasian really is gay or if he’s faking that sexual orientation to work Riedle to some ulterior purpose.

Badgering Minasian with questions and parrying his sullen answers, Kell eventually concludes that the Russian truly loved Riedle. Kell’s trust and regard for Minasian’s devotion to his lover becomes an affecting and significant aspect of “A Divided Spy.” Here, refreshingly, being gay is not shorthand for being perverted, repellent and villainous.

Charles Cumming (Jonathan Ring)

On his journey in “A Divided Spy,” Kell probes the psychologies of doubt, trust and persuasion, using them to get what he needs from other spies and “civilians” (wives, friends, lovers) and even what he seeks in his own life. The nature of his pursuit makes “A Divided Spy” a quiet thriller in which a character’s moment of awareness or a soft-spoken exit line can be breathtaking.

Against these nuanced moments, a timely subplot plays out that leads to a major action scene at the English seaside resort of Brighton, perhaps an homage to Graham Greene’s “Brighton Rock” rendered as a Hitchcock moment. Alas, the set piece seems obligatory and somewhat, in one of its aspects, implausible.

Far more suspenseful and consistent with the book’s overall tone is a final confrontation between a few men on a bridge in Gdansk, Poland. Kell handles the challenge with care, courage and sensitivity, bringing a note of grace to the treacherous world of the spy novel.

Gerald Bartell is an artist and writer in Manhattan.

A divided spy

By Charles Cumming

St. Martin’s. 356 pp. $26.99