It’s likely true of anybody who’s interested in history: he or she wonders what might’ve happened had the rush of time executed different swerves now and then.

But novelists are the people most prone to play those scenarios out to their logical extremes. Thus, readers have been invited over the years to envision England being conquered by Spain in the 16th century (Ruled Britannia, by Harry Turtledove), “Honest Abe” surviving his 1865 visit to Ford’s Theater (The Impeachment of Abraham Lincoln, by Stephen L. Carter), Alaska becoming a Jewish homeland (The Yiddish Policemen’s Union, by Michael Chabon) and the Cuban Missile Crisis precipitating a full-scale war (Resurrection Day, by Brendan DuBois).

Perhaps no bygone era or corner of the globe has undergone as many literary re-imaginings, though, as mid-20th century Europe. Speculations about how history might have been refashioned as a consequence of Nazi Germany’s victory over the Allied nations in World War II have powered works ranging from Philip K. Dick’s The Man in the High Castle, Jo Walton’s Farthing and Guy Saville’s The Afrika Reich to Len Deighton’s SS-GB and Robert Harris’ Fatherland.

Those last two novels, both incorporating murder mysteries into their “alternative history” plots, are cited by British attorney-turned-author C.J. Sansom as inspirations for his provocative new thriller, Dominion. Released so far only in the UK, it’s an espionage yarn that unrolls within a counter-factual world where Great Britain—after negotiating peace with Adolf Hitler following the 1940 Battle of Dunkirk—chafes under an increasingly authoritarian regime locked in goose step with the Nazis, no matter the psychological and human costs of that partnership.

Sansom is best known for penning a succession of crime novels set during King Henry VIII’s reign and starring hunchbacked lawyer Matthew Shardlake (Heartstone). Dominion, however, is a standalone work that takes place mostly in 1952 (interestingly, the year of the author’s birth) and builds around David Fitzgerald, a civil servant in the Dominions Office, where he helps administer the British Empire’s relations with its far-flung polities.

Along with his colleagues, Fitzgerald knows it’s safest to maintain an apolitical persona; the government of Lord Beaverbrook, a newspaper baron who has ascended to the prime minister’s seat, is quick to identify dissent and even faster to quash it, employing an expanded Special Branch and Auxiliary Police force. Yet in the wake of his small son’s accidental death, and with mutual sadness slowly separating him from his blond young wife, Sarah, Fitzgerald agrees to covertly feed information to the Resistance campaign led by an aging Winston Churchill.

Fitzgerald is no debonair James Bond. He’s seriously conflicted over his Resistance role, not just because he fears putting an unwitting Sarah at risk but because he has long concealed his Jewish heritage—a legacy that marks him out as a Nazi target. Fortunately, his spying escapades are initially pretty small beer. But after a former university chum, geology researcher Frank Muncaster, is incarcerated in a Birmingham mental hospital, Fitzgerald is among a group of activists—also including an enigmatic Eastern European woman, Natalia—who are charged with snatching Muncaster and ensuring his safe transport to the United States.

Why is the eccentric, acutely shy Muncaster such a hot property? It seems that in a state of intoxication, his elder, scientist brother shared with him top-secret weapons information, knowledge that could be dangerous in a world where Germany wages seemingly endless war on the Soviet Union, Hitler suffers from Parkinson’s disease and may soon perish, U.S. President-elect Adlai Stevenson prepares to take office (and overturn a dozen years of his nation’s isolationism) and new weapons technology falling into Nazi hands could alter the fragile balance of powers.

Of course the best-laid plans tend to go amiss. Muncaster, determined to off himself before he can be tortured for his secret, is not happy to be liberated by Fitzgerald & Co., and endeavors to flee their protection. Meanwhile, Gunther Hoth, a Gestapo officer well-practiced in hunting down Jews, is on Muncaster’s trail as well, and won’t hesitate to hurt the people closest to David Fitzgerald if that’s what it takes to complete his mission. All of this drama takes place as Beaverbrook’s government compounds public distress by rounding up Jews for expulsion from Britain, and London—through which Fitzgerald and his co-conspirators escape with Muncaster—is beset by a real-life air-pollution phenomenon, the Great Smog of ’52.

Dominion is plump with character studies, if light on the sort of action familiar from numerous spy novels. It’s more a slow-burning but captivating, 593-page political thriller rife with resisters and collaborators, none of them wholly virtuous or venal. And it proposes a raft of British historical figures who, under the circumstances outlined here, might ultimately have sided with the Nazis—speculation that could earn the author a flurry of outraged letters from those people’s descendants. Sansom also highlights the destructive potential of government policies rooted in nationalism and racial enmity, both of which, he observed in an essay for The Guardian newspaper, recently “came to the fore again in Europe as economic crisis gripped the continent ...”

Layered within all of that is the story of a man’s self-discovery and his development of moral courage. Fitzgerald finds the voice and vehicle to defy totalitarian oppression. But he must concurrently confront his growing attraction to the dark Natalia, who seems to offer a welcome escape from the psychological oppression he’s endured since his son’s demise. That latter challenge might scare off even the supremely resourceful Agent 007.

Sansom’s only other standalone historical novel, Winter in Madrid, debuted in the UK in 2006 but wasn’t long in reaching U.S. bookstores. Let’s hope Dominion enjoys that same fate.

 J. Kingston Pierce is both the editor of The Rap Sheet and the senior editor of January Magazine.