A 1929 dance hall explosion in a small Missouri town leave 42 people dead and many more maimed and wounded, but nobody knows who did it, how it was done, or why. Except maybe Alma, the maid, living in poverty but labouring in the houses of the well-off, who many years later tells the story to her grandson. Her wayward sister, a love-struck banker, an ex-con who can't shake his old life, Alma's parents and husband, Alma's sons, all their lives intertwine with others in this astonishingly powerful and sweeping book, laying bear a community and a society and ways of life that are exploded by an unsolved catastrophe.