The Dark King is the first short story published in the Horus Heresy series. The Dark King was first published in 2007 for exclusive release at a Games Day UK as part of the Horus Heresy Chapbook anthology book along with the short story The Lightning Tower. It was later released as an audio drama (MP3) with The Lightning Tower and again by itself enhanced audio edition e-book. The Dark King was later included in the Shadows of Treachery anthology novel. Cover photo taken from Enhanced Audio Edition E-book.