Dr. Cairn stepped closer to the dead man.
"Heart," he said. "He died of sheer horror."
He turned to Chambers, who stood in the open doorway behind him.
"The dressing-room door is open," he said. "I had advised Lord Lashmore to lock it."
"Yes, sir; his lordship meant to, sir. But we found that the lock had been broken. It was to have been replaced to-morrow."
Dr. Cairn turned to his son.
"You hear?" he said. "No doubt you have some idea respecting which of the visitors to this unhappy house took the trouble to break that lock? It was to have been replaced to-morrow; hence the tragedy of to-night." He addressed Chambers again. "Why did the servants leave the house to-night?"
The man was shaking pitifully.
"It was the laughter, sir! the laughter! I can never forget it! I was sleeping in an adjoining room and I had the key of his lordship's door in case of need. But when I heard his lordship cry out—quick and loud, sir—like a man that's been stabbed—I jumped up to come to him. Then, as I was turning the doorknob—of my room, sir—someone, something, began to laugh! It was in here; it was in here, gentlemen! It wasn't—her ladyship; it wasn't like any woman. I can't describe it; but it woke up every soul in the house."
"When you came in?"