The title might make “Anthropoid” sound like a science-fiction film, but actually it’s a docu-drama about the Czech government-in-exile’s 1942 operation to assassinate SS Obergruppenfuhrer Reinhard Heydrich, the brutal Nazi overseer of occupied Bohemia and Moravia and a prime implementer of the Final Solution—as well as the savage German reaction to the killing. More dogged than inspiring in the first half—even the assassination is rather flatly dramatized—it literally explodes in the last act, which depicts the prolonged, bloody showdown between troops and the assassination team in a Prague church.

As scripted by director Sean Ellis and Anthony Frewin, the film begins with archival footage, accompanied by captions describing Hitler’s takeover of Czechoslovakia in 1938-39 in an oversimplified fashion that suggests a readiness to deal with the historical record a bit loosely. (It implies that the Munich Conference of 1938 gave the Nazi regime a green light to seize the entire country, when actually it pressured the Czechs to turn over the Sudetenland to Germany peacefully. It was not until the next year that Hitler, betraying the pledge he had made at Munich, invaded the remainder of the country, proving that he was not interested merely in uniting all Germans under Nazi rule.) It then quickly establishes the cruelty with which the efficient but hated Heydrich ruled with an iron fist.

The treatment quickly shifts to late 1941, when Czech and Slovak soldiers parachute into the country from England, tasked with killing Heydrich to demonstrate the potency of the London-based government-in-exile. The focus is on Josef Gabcik (Cillian Murphy) and Jan Kubis (Jamie Dornan), who have a difficult landing, with Kubis injuring his foot and the duo forced to kill a man who pretends to help them but actually is an informant. They nonetheless make their way to Prague, where after proving their bona fides they connect with the tattered remnants of the resistance—Ladislav Vanek (Marcin Dorocinski) and “Uncle” Jan Zelenka-Hajsky (Toby Jones)—who, though they think the mission absurd, arrange for the two men to be taken in by the Moravec family, or more properly by Mrs. Moravec (Alena Mihulova), who keeps her husband (Pavel Reznicek) in the dark about their purposes, though her son Ata (Bill Milner), an aspiring violinist, will become a co-conspirator.

One of the fumbles of the film—in addition to the shaky-cam style adopted by Ellis, who served as his own cinematographer—is that it fails to convey much sense of chronology and planning for the assassination attempt (limited to a few scenes of Gabcik and Kubis spying on Heydrich, played by Detlef Bothe, with binoculars and getting information on his routine from the resistance). Instead it concentrates on the men’s relationship with a couple of girls, Marie (Charlotte Le Bon) and Lenka (Anna Geislerova), whom they recruit to make their wandering about the capital more natural. Of course, romance blossoms between Josef and Lenka on the one hand and Jan and Marie on the other; in fact, the latter two will eventually plan to marry.

In fact, one might be surprised when we abruptly find ourselves in May, 1942, when news that Heydrich is about to be transferred to Paris not only requires the mission to be carried out the next day. That brings to the fore the other parachutists involved, including Opalka (Harry Lloyd) and Bublik (Sam Keeley), who have been largely invisible until then. The attempt on Heydrich’s life as he drives to work quickly follows—a botched business, partially because one of the players, Karel Curda (Jiri Simek) gets cold feet. It does, however, leave the Nazi wounded—fatally, as it would turn out.

In the aftermath of the killing, the Nazis take terrible reprisals on the populace while searching for the parachutists, who seek refuge in a church at the invitation of its priest (Roman Zach). Unfortunately, information about them is revealed to the Germans by the turncoat Curda, which leads to the deaths of many of their local helpers, including Ata, who is tortured into revealing their whereabouts before he is killed. (Whether he was actually playing Bach when the Germans broke into the Moravec apartment, or whether the spirit of Lenka—who’d been killed by a soldier—actually appeared to Josef as he prepared to commit suicide, are questions for historians to ponder.)

That final assault on the church—which actually did drag on for two hours—is easily the most vivid part of the film, carefully choreographed and crisply edited by Richard Mettler, who elsewhere exhibits a more dilatory inclination. Unfortunately, even here Murphy and Dornan deliver performances that are more tentative than heroic. As played by Dornan, whose expressivity is distinctly limited, Kubis comes across as a particularly feeble character, unable to bring himself to shoot a dangerous fellow at the very start and not showing much spine afterward, until trapped at the end. Murphy is only slightly better, and one can’t help but feel that their superiors might have been better off assigning leadership of the operation to Opalka, whom Lloyd makes a far stronger figure. Neither Le Bon nor Geislerova make much of an impact either, and one will probably emerge from the film remembering supporting players instead—Mihulova and Milner, who play the doomed Moravecs, are especially strong, and Jones, though struggling with his accent (not as much as Murphy or Dornan, however), is his usual reliable self.

On the visual side “Anthropoid,” despite Ellis’ irritating hand-held camerawork, is impressive, with production designer Morgan Kennedy, art directors Radek Hanak and Michal Soun, set decorator Ussal Kalyoncu Smithers and costume designer Josef Cechota all doing expert work. The Prague locations naturally exude authenticity.

But in the end “Anthropoid” is no “Valkyrie.” Bryan Singer’s movie had problems of its own, but it managed to generate a sense of tension and desperation that Ellis’ doesn’t, until the last act. It’s a pity that the mission to kill Heydrich—rightfully remembered as an act of supreme heroism by Czechs—has resulted in a surprisingly turgid film that doesn’t spring to life until it’s almost put you to sleep.