Most students of World War II know of the British and Norwegian commandos who destroyed a heavily guarded hydroelectric plant in a remote mountainous region of Norway, a plant that was key to Nazi Germany's efforts to beat the Allies to an atomic bomb.

If the "heroes of Telemark" had failed and Hitler got the bomb, London might have disappeared in a blast and the Allies could have lost the war. "By God's mercy," Winston Churchill declared following the bombing of Hiroshima at war's end, "British and American science outpaced all German efforts."

In his latest book, Neal Bascomb — the acclaimed author of "Hunting Eichmann" and other nonfiction narrative histories — makes extensive use of diaries, memoirs, interviews with saboteurs' families and other original sources. Most of the story takes place in the Hardangervidda, a high wilderness plateau in Telemark, where rain and snowmelt cascade down steep valleys. Early in the 20th century, Norsk Hydro blasted tunnels to divert the water and power turbine generators.

Bascomb bravely tries to explain early research in nuclear physics, including the production of "heavy water" and how that mysterious liquid was essential to German efforts to build a bomb. Norsk Hydro's plant was the best place to produce it in necessary quantities.

But while the science is accessible and interesting, the heart of the story is how a small band of Norwegians escaped to England after Norway's surrender and occupation in 1940, how they trained with British commandos, developed an intelligence-gathering force back home and slipped back into Norway to deny Hitler that awful power.

As a Washington Post critic wrote of Bascomb's "Hunting Eichmann," — about the capture by Israeli agents of Nazi mass murderer Adolf Eichmann — the author sometimes "strains to build up tension" with his literary or "cinematic" technique. In scene after dramatic scene, from remote Norwegian mountain hideouts to research rooms in Berlin to commando training camps in Britain, he uses crisp dialogue, lavish description, deep character development and other literary devices. It makes for suspenseful reading and feels honest, but at times one almost hears the camera's whir.

We get to know these men, ordinary and extraordinary at the same time, loners and family men, scientists and laborers and students, fiercely patriotic. Many died. Of the raid's survivors, some remained in occupied Norway, taking up leading positions in the resistance.

"The Winter Fortress" is an intensely researched and vividly told account of one of the most critical episodes of the war, carried out by men who weren't always clear about the significance of their mission. But they believed that it had to be done despite terrible and unavoidable costs and that free people would honor their sacrifice and talk about it for a hundred years.

Chuck Haga is a former Star Tribune reporter who teaches at the University of North Dakota in Grand Forks.

The Winter Fortress
By: Neal Bascomb.
Publisher: Houghton Mifflin Harcourt, 378 pages, $28.
Event: 6 p.m. May 9, Norway House, 913 E. Franklin Av., Mpls.