Just under half the length of the novel tells how a discovery on the Moon brings Massachusetts linguist Robert Fairlie to a high-security space base in New Mexico and eventually to the planet Ryn.

Professor Robert Fairlie of Massachusetts University ponders that question when he is shanghaied and taken to Morrow Base, America's spaceport, in New Mexico.

At Morrow, with three other linguists drafted into the project, he learns that an American expedition to Gassendi crater has made a discovery which US authorities are keeping secret — machinery, documents and speech recordings left over from a battle thirty thousand years before.

They're to be supervised by the urbane Nils Christensen, chief of the Lunar Project, and the tightly wound and demanding Glenn DeWitt, whose background is military.

The secrecy surrounding the project has to do with the arms race — it is considered most important that secrets of advanced extraterrestrial technology will not fall into the wrong hands.

Acting on a playful hunch, Fairlie discovers that the language of the ancient Moon base has remarkable similarities to Sumerian and he begins translating the material brought from Gassendi.

On Ryn they land their ship next to the slagged remains of a once-great starport and the decayed ruins of the city that had stood by it, surrounded by forest.

Fairlie learns, from Aral and Thrayn, that people on Ryn still remember and fear their enemy in the ancient war, whom they name as the Llorn, and also call "the shadowed ones".

To show what they mean about evolutionary diversity, the Llorn lift the veil of shadow that surrounds them, revealing their physical forms — they are two-legged, two-armed humanlike beings, but their bodies differ in several visible ways from those of Earth people — for instance, they don't have necks.

Floyd C. Gale of Galaxy Science Fiction in 1963 rated the novel 4.5 stars out of five, stating that "Hamilton was extra careful with his story ending and you should be, to [sic].

[2] John Clute, a contributor to the Encyclopedia of Science Fiction, found the Haunted Stars "well-characterized", and thinks it is probably the best of a group of Hamilton novels which, "though in the space opera tradition", are "more carefully composed and darker in texture" than other works by the same author.

He writes that fifty years after its first publication, the Haunted Stars remains a "thought-provoking" work, which "explores the friction between scientific inquiry and the use of technology for military ends" and "raises profound questions about humanity’s behavior when confronted with an alien culture".

[3] According to M. Harold Page of Black Gate magazine, the Haunted Stars was written at the point when Edmond Hamilton's writing career overlaps with that of Arthur C Clarke.