Hallgrimur Helgason's novel "Woman at 1,000 Degrees" centers on Herra, an 80-year-old Icelandic woman waiting to die in a garage with an old hand grenade and a laptop.

This is, in part, a comic novel in the vein of Helgason's global bestseller "101 Reykjavik." But "Woman at 1,000 Degrees" contains a variety of tones as Herra moves back and forth through the decades of her life, with an emphasis on World War II. Although she hasn't detonated her grenade just yet, she is willing to throw a few bombs into her family's placid lives.

Helgason, who lives in Iceland, discovered the germ of this book when he made a phone call for a 2006 political campaign. On the other end of the line was Brynhildur Georgia Bjornsson, granddaughter of Iceland's first president. Her father was one of the few Icelanders who chose to fight with the Nazis in Germany. And she really was living in a garage.

With the character of Herra, Helgason has fictionalized Brynhildur's life, which she described in a memoir before she died in 2007. In Helgason's version, 12-year-old Herra is deposited by her father at the Hamburg train station to meet her mother in 1942. When she never arrives, the girl is forced to make her own way to safety.

"It's been more than two years since I became an orphan and entered the war from the Hamburg Central Station," she writes of a terrible day in 1944. "I've been roaming around the Reich of war, through ruins and raids, seeking shelter in shelters and sleeping in courtyards, attics, here and there. . . . And all this time I managed to fight off the hands of war and keep myself a child, all the way up to this eastern forest, all the way up to last night."

The life she leads is tragic, and in the end, readers will understand why Herra clutches her grenade so close. She has endured a bad marriage and had sons by a few different men. But not one of her adult experiences can compare to the hell of those teen years during the war.

Perhaps that's why Helgason chooses to have his narrator unspool her story and then reel it tightly back in at odd intervals. He is demonstrating how impossible it is for trauma survivors to make sense of their own lives. Numbed by deprivation, sexual violence and horrors she can't unsee, Herra tosses off anecdotes about a brief affair with John Lennon at the same pace she describes neglect by her children. She is the most unreliable of unreliable narrators, but her perspective might be just what we need in these uncertain times: She survives and shares her story on her terms. And what a story it is, one worth reading to further understand the complexity of World War II — and to enjoy the quick wit of a woman you won't forget.

Bethanne Patrick is the editor, most recently, of "The Books That Changed My Life: Reflections by 100 Authors, Actors, Musicians and Other Remarkable People."

Woman at 1,000 Degrees

By Hallgrimur Helgason

Translated from the Icelandic by Brian FitzGibbon

Algonquin. 391 pp. $27.95