In the tradition of When Time Stopped and The Hare with Amber Eyes, this subversive family memoir investigates the dark legacy of the author’s great-grandfather, a talented German-Jewish chemist who wound up developing chemical weapons and gas mask filters for the Nazis.

When Joe Dunthorne began researching his family history, he expected to write the account of their harrowing escape from Nazi Germany in 1935. What he found in his great-grandfather Siegfried’s voluminous, unpublished, partially translated memoir was a much darker, more complicated story.

Siegfried was an eccentric Jewish scientist living in a small town north of Berlin, where he began by developing a radioactive toothpaste before moving on to products with a more sinister military connection—first he made and tested gas-mask filters, and then he was invited to establish a chemical weapons laboratory. By 1933, he was the laboratory’s director, helping the Nazis to “improve” their poisons and prepare for large-scale production. “I confess to my descendants who will read these lines that I made a grave error,” he wrote. “I cannot shake off the great debt on my conscience.”

Armed only with his great-grandfather’s rambling, nearly two-thousand-page deathbed memoir and a handful of archival clues, Dunthorne traveled to Munich, Ammendorf, Berlin, Ankara, and Oranienburg—a place where hundreds of unexploded bombs remain hidden in the irradiated soil—to uncover the sprawling, unsettling legacy of Siegfried’s work. Seeking to understand one “jolly grandpa” with a patchy psychiatric history, Dunthorne confronts the uncomfortable questions that lie at the heart of every family: Can we ever understand our origins? Is every family story a work of fiction? And if the truth can be found, will we be able to live with it?

Children of Radium is a witty and wry, deeply humane and endlessly surprising meditation on individual and collective inheritance that considers the long half-life of trauma, the weight of guilt, and the ever-evasive nature of the truth.