Hostia III was dead. The First Company of the Death Guard was meant to deal with a small insurgence, but the rest of the fleet lost contact with the Terminus Est shortly after it entered the warp. In itself, it was nothing unusual and so the Expedition Fleet wrapped up its business before following the course the lost ship was meant to take. Once they left the warp they were met with the sight of a devastated world, whole continents covered in rot.
Senshi Saturn was forced to bring her glaive down upon it, forever silencing whatever illness had wracked it. Only once the planet was void of any life, down to the most insignificant bacterium, did the First Company make contact.
Mortarion watched the message, but the sense eluded him. It was garbage in written form. He crumpled the note in his massive fist, rage building inside him. While most of the communiqué was nonsense about some "Father Nurgle" and transgressions against his love for all life, one point was all to clear. Typhon claimed Persephone was an abomination and admitted to releasing the plague on Hostia III. That would not be forgiven.
"My Lord," Grulgor said, "Will we not let Calas explain himself?"
"I see nothing to explain," Mortarion said quietly.
"Somebody may be trying to frame him," Grulgor persisted.
Mortarion's look was frigid and the 2nd Captain fell silent, cowed by his Primarch's silent fury.
"Sir!" one of the operators cried from the bridge. "Terminus Est has appeared in our sensors."
"Fire at will," Mortarion drawled. "Traitors deserve no warning."
For a moment the bridge was abuzz, as the information was being relayed to the other ships. Then, suddenly, the same operator called out:
"Sir! Terminus Est entered the Warp!"
Mortarion remained outwardly calm, more like a statue as the noise died down. Typhon had apparently counted on exactly this kind of reaction from his Primarch. The silence slowly drowned everything else, its icy tendrils reaching into the hearts of those presents. Fear was beginning to awaken, when Mortartion spoke again.
"We are heading to Barbarus."
Even if Typhon knew how Mortarion thought, the same applied the other way around and Mortarion was still the smarter one. If Typhone wanted to play catch, he would find himself outmaneuvered.