“No,” Grace said dully. It was the truth. One did not lightly anger such a powerful demon. “But if you—and your patron—wished to prevent this wedding, you should have acted earlier than this.”

Tatiana sneered. “I trusted you would act on your own. It seems that was foolishness. You have known how to contact me, with the adamas, but you have never bothered. As always you disappoint.”

“I was afraid,” Grace said. “The Bridgestocks—he’s the Inquisitor, Mama.”

“It was your choice to live in that lions’ den. As for the wedding, it hardly matters. Making Herondale betray his vows is a delicious prospect. He will hate himself even the more for what our power has wrought.” Tatiana’s face split into a rictus grin; it was terrifying, wrong, somehow, as if the human face she had borrowed were about to come apart at the seams. “I am your mother,” she said. “There is no one in this world who knows you as I do.” Jesse, Grace thought, but she said nothing. “I saw the look on your face, downstairs. You intended to release him again, didn’t you? You intended to confess?”

“There is no point to all this,” Grace said. “The magic is not strong enough. I cannot bind him forever. He will see through it, you know, through the falsity.”

“Nonsense.” Tatiana made a dismissive gesture, the housemaid’s wrist flopping bonelessly as she moved. “You understand nothing of the greater plan, girl. James Herondale is a piece on a chessboard. Your duty is to keep him in place, not tell him secrets he has no business knowing.”

“But he will not do as I say—”

“He will do what we need him to, if you bend your will to it. It matters only that you do as you are told.” Her shoulders twitched, violently; Grace was reminded of stories she had heard about animals, still alive, writhing inside the bodies of snakes who had swallowed them. “And should you think of disobeying, our patron is prepared to cut you off from any access to Jesse. His body will be taken to where you can never see him again.”

Terror went through Grace like a knife. The demon could not know, could he, what she had been planning, hoping to do to help her brother? “You cannot,” she whispered. “You cannot let him, Mama—I am so close to helping Jesse—you would not separate us—”

Tatiana laughed; just then the door rattled in its frame. The housemaid’s face contorted; she gave a violent shudder and collapsed to the ground. Her broom and dustpan went flying. Grace raced to her side as the door flew open and someone said, “Miss Blackthorn! Miss Blackthorn, what happened?”