At dawn, the orchard held a new honesty. The Sisters' nulls were distant; the wards low and wide. Mortarion stood in the clean light like a man waiting to be judged. He had learned to distrust power that touches minds; Barbarus had taught him to breathe other men's poison.
"Breathe," Aurelia said. "Only that."
He did, and the air did not take anything from him. Not strength, not anger, not will. Whatever unseen craft had prepared the morning, it only returned what poison had kept. "If power can make miasma fade," she asked, "must we hate the hand that wields it?"
He did not answer. But later, on a wall walk, a Custodian watched the Lord of the Death Guard unfasten a rebreather seal and close his eyes as if remembering the word clean. He refastened it with a click that sounded almost like gratitude.
Mortarion broke the quiet first. He found, to his irritation and relief, that in her company the air in his chest settled; around her, the itch of old poisons retreated. This stretch of wall had become the place he could breathe and speak plainly. "You are the heir," he said. "A psyker who says she is not. How am I to trust you will not become what I was born to kill? Kindness blinds. Empires that mean well still crush what lives beneath them."
Aurelia did not flinch. "If that day ever comes," she said, "I want you present. Show me the hurt my rule makes. Name it so I cannot look away—and act as you must."
The rebreather hung from his fingers for a long breath. "I will hold you to that," he said at last.
"Good," she answered. "So will I."
The Custodian, still as the merlons, wrote none of it in any book, but remembered the click when Mortarion resealed his mask: not gratitude now, something sterner—consent