One moment he had been talking with someone at the party, the next he was suddenly alone. He was still at the party - the setting had not changed - but the hall was empty. The ringing sound of people chattering to each other all through the party disappeared. He was alone, and the shadows stretched and twisted in weird ways all around him.

He frowned, taking a step forward, and heard a chuckle behind him. He recognized that voice. He recognized it.

His blood chilled as he turned - just enough to peer behind him - and saw the figure. Tall, dark, and the light wouldn't seem to touch him - bending away before it could illuminate his features, but Sherlock already knew who it was. Knew who held the knife in his hand, knew who laughed before pulling up a finger to his lips and making a low sound. Shhhh.

Knew who it was when the figure turned away to look for prey.

It was him.

"No!" Sherlock called out after the shadow as it slipped away, and he lunged after it. "Stop!"