I left them, and passed on into our studio sitting-room, where Mabane was filling his pipe.

"What's the matter with Arthur?" I asked.

"Off his chump," Allan answered gravely. "Don't take any notice of him."

Isobel and he were still talking together. Arthur's voice was a little raised—then it suddenly dropped.

"I think," Allan said, "that you had better interfere. Arthur has lost his temper. I am afraid——"

"He will break the compact?" I exclaimed.

"I am afraid so!"

I stepped back into the little hall. They were talking together earnestly. Arthur looked up and glared at me.

"Arthur," I said, "Allan and I want a few words with you before you go—if you are going out to-night."

"In a moment," he answered. "I have something to say to Isobel."