Emily Strasser's debut book, "Half-Life of a Secret," begins with a photograph, one that hung in her grandparents' lake house: It's of her grandfather, George, (who died before Strasser was born) standing in front of a mushroom cloud made by a nuclear blast.

Strasser thought little of it until years later when it occurred to her that perhaps, "the world wasn't as it had appeared," for the image didn't correspond to the idyll her grandparents had built: long summer days swimming with cousins, catching sunfish and watching the "mirror-still lake" as "a heron rose like a ghost from the opposite shore, crossed the distance with steady, slow wingbeats, and landed on our dock."

And so begins this beautiful, nimble excavation of a family photograph and the fallout of its legacy.

George lived and worked as a scientist in Oak Ridge, Tenn., one of three cities secretly built to develop the atomic bomb. To make such a town, farmers were removed from the land, and before them, sharecroppers, Cherokee and others "who'd loved and lost this land."

Strasser asks of her family, her country: "What is it to love a home founded on such violence for the sake of further violence?" Strasser's main barrier is that the person she seeks to understand — George — can't speak for himself, so she turns to the evidence he left behind.

Thing is, Strasser can only locate the photograph in her memory, which she doesn't always trust. Not because she's an unreliable narrator, but because memory is impossible to pin down, and the secrets she's poking at don't want to be found. But poke she does.

Strasser — a graduate of the University of Minnesota MFA program — consults the archival and the autobiographical by querying not just memories of family and friends but newspapers, medical records and museums.

Each revelation, however, is encumbered by a nest of additional surprises, which feel like tiny bombs themselves, reminiscent of Sven Lindqvist's "A History of Bombing," which deploys a narrative structure mirroring the scattered path of a bomb's shrapnel.

Strasser's personal queries become global concerns and her book questions, as does Lindqvist's, the morality of aerial bombing. From Guernica to Rotterdam to Nagasaki, bombing has long been justified as a deterrence to additional violence, its positive impact superseding its negative. So Strasser consults the numbers: How many lives were saved to how many lives were lost?

She realizes quickly: "To tell a story, one must decide what counts and in what order." Meaning, whose lives were saved, whose were lost, and why.

Was it better / easier / more justified to annihilate the "Asian other" in Hiroshima than it was to destroy the (white, middle-class-looking) mannequins as was done at the Nevada Proving Grounds she visits? And what of the subsequent deaths, she wonders, those perhaps caused by the "toxic wastes burial grounds" in Oak Ridge or the fallout from radioactive dust?

Strasser's prose reaches beyond the straits normally reserved for academic presses in which this book was published, and her patience against some of the biggest ethical questions humans face is a thing of great strength. A profound debut of memory, research and imagination that mines conflicts of heart and intellect.

Kerri Arsenault is the author of "Mill Town: Reckoning With What Remains."

Half-Life of a Secret

By: Emily Strasser.

Publisher: University Press of Kentucky, 336 pages, $26.95.

Events: In conversation with Kathryn Savage, 7 p.m. April 4, Magers & Quinn, Mpls.; 6 p.m. April 24, Next Chapter Books, St. Paul.