“On a matter of life and death,” he repeated to himself. “Those words are more serious, perhaps, than you think. What do you mean?”

“What I say.”

The perspiration broke out thickly on his broad forehead. His left hand stole over the edge of the table. There was a drawer in it, with a lock, and the key was in the lock. His finger and thumb closed over the key, but did not turn it.

“So you know why I am leaving London?” he went on. “Tell me the reason, if you please.” He turned the key, and unlocked the drawer as he spoke.

“I can do better than that,” I replied. “I can show you the reason, if you like.”

“How can you show it?”

“You have got your coat off,” I said. “Roll up the shirtsleeve on your left arm, and you will see it there.”