Stirling later wrote a short story prequel, "Sword of Zar-Tu-Kan", which was published in the 2013 anthology Old Mars, edited by George R. R. Martin and Gardner Dozois.

Those present include Frederik and Carol Pohl, Poul Anderson, H. Beam Piper, Guest of Honor Theodore Sturgeon, Jack Williamson, Robert and Virginia Heinlein, Arthur C. Clarke, Larry Niven, Isaac Asimov, L. Sprague and Catherine Crook de Camp, John W. Campbell, Frank Herbert, and Leigh Brackett.

The former mercenary now commands the power of an ancient technological artifact allegedly created by the aliens that terraformed Mars and Venus and seeded them with life from Earth.

That forces her, with the help of her father's soldiers, to attempt to rescue him from the fortress of a potential usurper, who had been displaced from the imperial succession after the emperor recognized his daughter's legitimacy.

The crown prince is later defeated after playing a game of Atanj (Martian chess), using people as the pieces, including Teyud and Jeremy.

Publishers Weekly called it "charming", and praised Stirling for "successfully creat[ing] a truly alien environment", but criticized his "inclusion of pirates with eye patches, heavily armored guards riding 'fat-tired, self-propelled unicycles' and other moments of near-parody.