The End and the Death: Volume I - Dan Abnett

There is no way out.

The walls have fallen, the gates are breached, and the defenders are slain. It is the end and the death. After seven brutal years of civil war, the Warmaster stands on the verge of victory. Horus Lupercal, once beloved son, has come to murder his father. The Emperor, a shining beacon of hope to many, an unscrupulous tyrant to others, must die.

The lives of uncountable numbers have been extinguished and even primarchs, once thought immortal, have been laid low. The Emperor's dream lies in tatters, but there remains a sliver of hope. Now, at the final hour of the final day, the Emperor rises. With him come his Angel, his Praetorian, and his Captain, all determined to enact terrible vengeance. Yet the hope is slim, for the Warmaster sees all and knows all, and the ultimate victory of Chaos is at hand.