"I must warn you that I'll send you a bill for any medical advice I give you," I replied, laughing.

She smiled only a little and then puckered her brow seriously.

"I wanted to ask you about that operation. Wasn't it performed under unusual circumstances?"

I was taken by surprise and I am afraid that the truth forced its indications through my professional manner. "Why do you ask?"

"I noticed Blake standing near the door. There seemed to be a bulge in his pocket. It couldn't have been a gun, could it? And you kept watching, as if you were afraid a tribe of Indians would drop in for a massacre. I wonder if there couldn't have been a tall, dark gentleman mixed up in these unusual precautions?"

I did not reply.

"And I've noticed during my convalescence that the internes that continually hover around my door have a look as if—well, shall I say that they look more like policemen than internes?"

I laughed nervously. "I think you are a mental case, Miss Mayo," I said. "I shall have to call in a specialist."

"You do not need to deny it, Fred," she said. "Why do you suppose I insisted that you perform the operation? Why didn't I let you call in someone else? It was because you are the only man in the world that I trust, Fred. How much did Gustav Keeshwar offer you to do me in?"

Before I could stop myself I opened my mouth and blurted the truth.