Clemantine Wamariya fled genocide in her native Rwanda when she was 6 years old. She and her 15-year-old sister Claire were on the run for the next six years, hiding out in banana groves, living in refugee camps, hauling jugs of water, digging flesh-burrowing bugs out of their feet, foraging for firewood, sleeping on cardboard, sleeping in mud, eating maize and beans, maize and beans, maize and beans, eating grasshoppers, crossing raging rivers in leaky boats, walking for days, trying to stay clean, trying to stay human.

All of Clemantine's toenails fell out. She had to have her head shaved, to get rid of the lice. She was exhausted all the time. She was a child of 6, then 7, then 8, 9, 10, 11. "Staying alive was so much work," she writes in her unforgettable memoir, "The Girl Who Smiled Beads." "I was hungry, I was thirsty, I needed a bathroom, I needed a place to sleep. I was so confused. I just kept spinning."

Wherever she was, she tried to keep herself and her scrap of shelter clean. She railed against other children in the camps: "I couldn't stand the naked two- and three-year-olds. They looked to me like strays — filthy, unloved, drooling, bugs crawling on their faces, flies around their eyes that nobody bothered to swat."

She yelled at them to put on some clothes. She was terrified she would forget what it meant to be civilized. To be human.

For six years, she and Claire moved around Africa, from Rwanda to Burundi to South Africa to Tanzania to Zambia to Zaire and back to Rwanda. Mostly, they walked. They did not know where their parents were, nor their brother. Claire's dreams of studying at McGill University were long gone; instead, she became skilled at bartering and hustling.

Clemantine saved rocks in her Mickey Mouse backpack, one from each place they stayed, "to keep track of where we'd been." When she lost the backpack, she was inconsolable. Earlier she had described her fear as "bright blue." Now, her rage was "dark red."

This gripping memoir follows two parallel tracks: Clemantine's life on the run in Africa, and her life in the United States, where she was granted refugee status at the age of 12.

Her fury did not abate in the U.S. She is deeply grateful to the foster mother who took her in, gave her space and calm, bought her clothes, helped her with school. Mrs. Thomas "understood my fear of being lost or left behind," Clemantine writes. With Mrs. Thomas' help, Clemantine was accepted into Yale and graduated with a degree in comparative literature.

But life in America ("the ultimate land of hustle and reward") had its own terrors. Once the wearying grind of finding food and water was lifted and she was safe, she was engulfed in trying to deal with her trauma and grief. In school, when the class studied genocide, she fell apart.

The agony of displacement does not magically vanish in a new, safer country. Even after she was reunited with her parents — in the oddest possible way, on Oprah Winfrey's television show — the break could not be mended. The damage of years of war and separation was not easily repaired. At age 30, she is still working on it.

Memoirs by immigrants and refugees are growing in number; they are important stories that need to be told, and told in the kind of bug-and-mud-and-dysentery detail that Wamariya's is told.

Especially now, with families walking for weeks across Mexican deserts only to be separated in the United States, this book is crucial. It is our human tragedy that there will always be war, and that there will always be displaced people. Memoirs that show exactly what that means, exactly what the toll is, are vital.

Laurie Hertzel is the senior editor for books at the Star Tribune.

The Girl Who Smiled Beads: A Story of War and What Comes After
By: Clemantine Wamariya and Elizabeth Weil.
Publisher: Crown, 275 pages, $26.