A thousand sons by Graham McNeil is the 12th book of the Horus Heresy series which takes place before the Warhammer 40k universe. This book follows the tragic tale of the 15th Legion. After being reprimanded by the Emperor for dabbling in the dark arts, Magnus the primark of a thousand sons tries to halt Horus’s path to heresy, which has great consequences to him and his legion.
eBay