Luna Mendax is the eleventh short story published in the Horus Heresy that was not originally part of an anthology novel. It was originally included in The Black Library Anthology 2013/14 which was released exclusively at the Black Library Weekender Event in November 2013. Luna Mendax was later released as an individual e-book on January 25, 2016 as part of the "Tales of the Knights Errant" week on the Black Library's website. It is also now included in The Silent War anthology novel. Covers for both the original and updated artwork is shown.
Returning from a secretive mission to Caliban at the command of Malcador the Sigillite, the Knight Errant Garviel Loken finds sanctuary in one of the abandoned bio-domes of Luna. Scarred by betrayal and bewildered by the changing face of the galaxy, the weary warrior is almost unsurprised when he is visited by the long-dead Tarik Torgaddon –- is this a sign of a fractured and exhausted mind playing tricks on itself, or truly the spirit of a departed friend?
- Luna Mendax (Short Story) by Graham McNeill