On a Victorian pleasure cruise, a chance encounter opens the floodgates to regret, desire, and possibility in this 'little period gem of feeling and clarity' (The Guardian). It is 1851, only three years since Europe was convulsed by workers' revolutions, but already English tourists are returning to the Continent, taking the waters at Baden Baden, then traveling by paddle steamer down the Rhine valley, celebrated for its romantic vistas. Among the sightseers are the pious Reverend Charles Morrison, his wife and daughter, and his maiden sister, Charlotte, a seemingly meek middle-aged woman who's spent her life attending to the needs of others. Like the river upon which they're traveling, however, Charlotte contains hidden depths. A chance encounter with a fellow passenger in Coblenz sparks a Damascene moment, unleashing in her a sudden and violent awakening of memory, fear, and sexual desire. As the travelers are swept onward to Cologne, Charlotte wrestles with what Lauren Groff in her