Nemesis (Novel)

"War within the shadows"

- Book's tag-line

'Nemesis is the thirteenth book in the Horus Heresy series

Plot Summary
Nemesis is set about two years after the events on Istvaan V described in Book 5, Fulgrim. It deals with a plan by a secret Imperial organization, the Officio Assassinorum, to eliminate Horus using an Execution Force drawn from all the "clades" (specialist assassin schools) that make up the Officio.

There have been several previous unsuccessful attempts against Horus' life, and this gives a high-ranking officer of the Word Bearers Traitor Legion the idea to field a nemesis weapon of his own (a highly specialized assassin) in an audacious scheme to kill the Emperor.