Skylark DuQuesne

Written as Smith's last novel in 1965 and published shortly before his death, it expands on the characterizations of the earlier novels (written 1919 - about 1938) with some discrepancies (some of which may relate to unwritten background developments).

Marc DuQuesne, the major villain of the three previous novels, is shown to have matured, reformed, and been offered a chance at what amounts to a pardon for his prior crimes against the heroes.

The book ends with Dick Seaton and DuQuesne teaming up to perpetrate a galaxy-wide genocide against the Chlorans, causing all their suns to go nova.

The Chlorans themselves, though depicted earlier in the book as extremely cruel, were not bent on exterminating humans but only enslaving and exploiting them.

Skylark DuQuesne was first serialized in IF Worlds of Science Fiction beginning in June 1965 before being published in 1966 by Pyramid Books.