It originally appeared in the December 1951 issue of Galaxy Magazine and was dramatized on the radio show X Minus One in March 1956.

The story is narrated by a ten-year-old boy living on Earth after it has become a rogue planet, having been torn away from the Sun by a passing "dark star".

The boy's father had worked with a group of other scientists to construct a large shelter, but the earthquakes accompanying the disaster had destroyed it and killed the others.

He managed to construct a smaller, makeshift shelter called the "Nest" for his family, where they maintain a breathable atmosphere by periodically retrieving pails of frozen oxygen to thaw over a fire.

They reveal that other groups of humans have survived at Argonne, Brookhaven, and Harwell nuclear research facilities as well as in Tannu Tuva, and that plans are being made to establish uranium-mining colonies at Great Slave Lake or in the Congo region.