In the after-battle report, filed from the Blackstar in low orbit, Roth added a single entry to the digital copy of Mark of the Xenos :
Thorne raised his combi-bolter. “Then we burn them now.”
His savant, a pale woman named Helix, held a trembling auspex. “My lord… the bio-signature is wrong. This ship fell in 789.M41. But the cellular decay suggests… three months.”
The world screamed.
Thorne fired.
Thorne’s power fist crackled. “Impossible. The Hive Fleet was broken here.”
“Hive Fleets learn,” Roth whispered. He produced a slender, barbed stiletto—a xenos artifact marked with a forbidden rune. “This is the Mark . Not a brand, but a resonance. A psychic echo left on any world the Devourer touches. It draws the stragglers. The new strains.” Warhammer 40K - Mark Of The Xenos.pdf
“Tell me again why we are defiling this grave, Roth,” grumbled Watch-Captain Thorne of the Deathwatch. His black-armored form was a statue of disgust, the silver Inquisitorial I on his pauldron reflecting the sickly green sky.
Roth closed his eyes and pressed the data-quill to his own palm, carving the rune of the Mark into his flesh. “Let them see me. Let the Hive Mind know: the Inquisition watches. And we take notes.”
He plunged the blade into the dead flesh. In the after-battle report, filed from the Blackstar
The first xenos dissolved into a cloud of acidic mist. The second melted into the mud. The third… was already behind them.
“No,” Roth said, standing. He pulled a data-quill from his coat and began sketching the creatures as they stood motionless, watching back. “We document. We update the holy text. That is the true war, captain. Not bolter fire. Knowledge . By the time your brothers learn to fight these, the Hive Mind will have spawned three more variants.”