Marneus Calgar: Lord of Ultramar (Black Library Advent Calendar 2013 #20)

In the aftermath of the Bloodborn invasion of Ultramar, Marneus Calgar meets with his Chief Librarian in the shadow of their primarchs stasis-tomb. As they reflect upon the hardships of the past year and contemplate the future, both Tigurius and his Chapter Master realise that difficult decisions must be made and a powerful enemy must be faced, lest Ultramar suffer greater losses still. A Lords of the Space Marines short story By Graham McNeill