"Emperors and slaves"
- —Book's tag-line
Angels of Caliban is the thirty-eighth volume in the Horus Heresy series of novels. Angels of Caliban is the sequel to The Unremembered Empire (Book 27), and Pharos (Book 34), and the prequel to the upcoming novel Nightfall.
Two infamous Space Marine Primarch rivals clash for the final time.
With the Dark Angels Legion spread across a hundred systems, Primarch Lion El'Jonson stands as Lord Protector of Ultramar -- though his true motives are known to few indeed, and old rivalries on the homeworld threaten to tear the Legion in half. But when word comes of the Night Lords' attack on Sotha, the Lion's brutal actions bring Imperium Secundus once again to the brink of civil war. Not even the most fearsome warriors of the Dreadwing, nor any arcane secret of The Order, can guarantee victory if he sets himself against his loyal brothers.
- Angels of Caliban (Novel) by Gav Thorpe