At its core, espionage is about trust and betrayal. Cumming, a standout in the echelon of newer writers of spy fiction, probes the toll betrayal takes on a spy and the civilians in the orbit of those involved with the secret world of intelligence. The end of the Cold War and the struggle between the West and the East Bloc has freed writers to probe this aspect of espionage, often through plots that place the players in environments far from the struggle to gain an edge in the battle for superpower supremacy.

In this third installment in the Box 88 series, Lachlan Kite must reckon with his early experience of a failed operation in Senegal, decades after it occurred. Kite, who first appeared first as a teenage graduate of an English boarding school recruited into a highly classified Anglo-American intelligence unit known as Box 88, is now a middle-aged new father, struggling to repair his marriage and delight in his infant daughter. While he slowly rebuilds trust with his wife, each of them navigating a careful balance between secrecy and openness, an old school friend, Eric Appiah, makes an oblique approach to contact him in London, raising the specter of his first defeat as a spy.

In 1995, Kite and his girlfriend, Martha Raine, are dispatched to Senegal to pursue an architect of the Rwandan genocide, in which as many as 1 million people from the minority Tutsi tribe were brutally slaughtered by the majority Hutu tribe in less than 4 months, often hacked to death by machetes. Augustin Bagaza, a Hutu genocidaire, fled the chaos with his mistress Grace Mavinga and is laying low in Dakar, under the protection of French intelligence.

At 24, Kite has earned his stripes as a spy, but this operation seems slipshod and hastily conceived, and it unravels spectacularly. Kite keeps Martha in the dark about the real purpose of their trip, and when she takes ill, he focuses on the mission, essentially abandoning her in the care of Appiah, now a Senegalese son of privilege who treats Dakar as his playground. Appiah has more going on under the surface, and plays a role in attempting to capture the two fugitive war criminals.

When Lachlan leaves Senegal, he has three men's deaths on his conscious, Mavinga is in the wind, and the young spy is at sea in is relationship and his sense of purpose.

When Appiah reappears in 2023, he enlists Kite and a few surviving members of the original Box 88 team to pursue Mavinga, who has resurfaced after decades on the run, under the protection of former French intelligence officer Yves Duval. Duval's spectacular wealth is a sore spot for other members of the Deuxieme Bureau, since he made his fortune by doing the dirty work of money laundering for the same people he targeted while on active duty. The dui isn't afraid to play dirty, and strike back with vicious lethality.

Time-hopping over the decades, Cumming's plotting is taut, and his exploration of Kite's interior turmoil in both eras is perceptive and nuanced.

As Kite's team tightens their net around Mavinga and Duval, the action and tension ratchet up at a relentless pace, and when Box 88 achieves its objectives, the victory is bittersweet. Kite has lost more friends, faced up to the damage his intelligence career has done to the people around him, inside and outside the secret world.

Cumming has written 10 books since he himself was recruited by MI6 in 1995, and knows the drudgery and sometimes bleak interior lives of Secret Intelligence Service officers, but has also refined his craft as a writer of pulse-pounding plots and action sequences. The cliffhanger finish of Kennedy 35 will keep fans of the series wanting more.

KENNEDY 35 | By Charles Cumming | HarperCollins | 336 pp. | $27.95