Serpent is the tenth short story published in the Horus Heresy that was not originally part of an anthology novel. It was first published as an event-exclusive Horus Heresy Short Story that was printed upon the programme for the Horus Heresy Weekender held in Nottingham UK, on the 18-19/5/2013 and is written by Black Library author John French. It was later republished as an unabridged audio book. It is now also included in the Legacies of Betrayal anthology novel. Cover art shown is from unabridged audio-book version.