The Great Rift tears the Galaxy apart, Mephiston is enveloped in darkness and is visited by prophetic visions. At this hour, when he desperately needs the third Eye, an inexplicable force blinds the Chief Librarian of the Blood Angels. Plagued by the ghosts of the dead, Mephiston travels with his warriors to a planet called Morsus, where he believes the cause of his mental blindness lies. However, conflict has also broken out on this world - a long-standing confrontation between the Imperium and an incredibly ancient enemy. Thus, the Blood Angels are drawn into an unwanted battle, during which the secrets of Morsus and its inhabitants are revealed. Secrets far more dangerous than Mephiston dared to imagine.