- "The angel falls"
- —Book's tag-line
Fear to Tread is the twenty-first volume in the Horus Heresy series of novels.
Fear to Tread takes place upon the war-torn world of Signus Prime. Warmaster Horus sends the Blood Angels Legion to the Signus system on a fool's errand, where a large host of Chaos Daemons awaits them. The Warmaster's plan is to exploit the flaw in the Blood Angels' gene-seed (which will later be known as the Red Thirst) in order to turn them to the worship of the Blood God Khorne. The Blood Angels are forced to fight for their very survival of both their minds and bodies. At the height of the battle, Primarch Sanguinius is confronted by the mighty Bloodthirster Ka'Bandha.
- Fear To Tread (Novel) by James Swallow