His eyes began to burn, though they were closed. He felt breathless and sick, as if he’d dived under salt water and come up for air too late. Something was wrong. With a choked gasp of nausea, he broke away from Grace.

Her hand went to her mouth. There was a look on her face he had not expected—a look of undeniable panic.

“Grace—” he began, when the air was suddenly cut through by the sound of screams, coming from the lake. And not just one person screaming, as Oliver had called out last night, but multiple voices, crying out in fear.

James caught hold of Grace and pushed her toward the folly. She had no idea how to fight—had never been trained. She was still looking at him in horror. “Stay here,” he demanded, and bolted toward the lake.

Cordelia didn’t see it happen. By the time she had unsheathed Cortana, the demon had sprung from the water and directly onto Piers Wentworth. He went down with a howl of pain, kicking and thrashing.

There was instantly a melee. Shadowhunters were screaming—some had leaped for Piers, including Alastair and Rosamund, and were trying to peel the creature from his body. Charles had shoved Ariadne behind him—she looked exasperated—and was shouting for everyone to get away from the lake. Barbara was screaming, words that sounded like “What is it? What is it?”

But Cordelia could think of only one thing: Alastair. She raced toward the shore. She could see Alastair’s bright hair among the scrum of people. As she neared them, she saw Piers lying motionless by the water’s edge: the rim of the water was scarlet, and more scarlet was billowing into the lake. Rosamund was on her knees beside him, screaming. The demon had vanished, though Cordelia had not seen anyone kill it.

Alastair had backed away from Piers; Ariadne was on her knees next to the fallen boy, her dress in the blood and sand. As Cordelia drew near to her brother, she saw that there was blood on him, too. She reached him among the chaos, breathless.

“Alastair—”

There was a stunned look on his face. Her voice shook him awake: he caught at her free arm and pulled her toward the grass. “Cordelia, get back—”

She looked around wildly. Shadowhunters were running everywhere, knocking over hampers and trampling picnic food underfoot. “What happened, Alastair? What was it?”

He shook his head, his expression bleak. “I have absolutely no idea.”