Earth's Last Citadel is a novel written by the husband and wife team of C.L. Moore and Henry Kuttner

Henry Kuttner

Henry Kuttner was an American author of science fiction, fantasy and horror.-Early life:Henry Kuttner was born in Los Angeles, California in 1915...

. It was first published in 1943 in the magazine Argosy

Argosy (magazine)

Argosy was an American pulp magazine, published by Frank Munsey. It is generally considered to be the first American pulp magazine. The magazine began as a general information periodical entitled The Golden Argosy, targeted at the boys adventure market.-Launch of Argosy:In late September 1882,...

and in book form it was published first in 1950.

Plot

During WWII, four people (two Allies, two Axis) find a strange vehicle in the Tunisian desert. It whisked them to the far future where the Earth has been conquered and mankind is nearly extinct.