The story is set in 1888 in Iowa during a punishing, deep winter. Elias Thorne, a weary but resilient farmer, and his wife, Clara, are enduring a relentless deep freeze when the weather takes a sudden, terrifying turn. On a frigid morning, the temperature plummets to freezing. However, a break in the clouds unveils an intense, summer-like sun. Within hours, the temperature soars to an incomprehensible rise in the middle of January. This sudden, unnatural heat turns the massive snowpack into a catastrophic torrent of meltwater.