They are ambushed by scuttling skull-faced things in the armour of marines. They fight hordes of mutated beasts. One by one they die. In the end the Emperor stands alone. Then and only then is he allowed to enter the presence of Horus.

The Warmaster bestrides the body of a broken angel. Behind him the tortured Earth fills the viewport, a bauble for Horus to seize with one clawed hand. Corpses of massacred marines lie everywhere.

Face glowing with internal bloodlight, Horus speaks. "Poor Sanguinius. I offered him a position of power in the new order. He could have a seat at the right hand of a god. Alas he chose to align himself with the losing side."