My chief received my oath without any indication of belief or disbelief.
“I don’t blame you for anything else you did on behalf of Lady Violet,” he said gravely. “Even if you hadn’t been in love with her, as a man you could do no less than you did to save her from such a scoundrel. You were right to drug him and right to destroy his case-book. But you had no right to take his life.”
I looked him in the face. I was too proud to repeat my denial.
“That has been my greatest anxiety in the whole business, Cassilis. I liked you; you knew it, and I think you should have confided in me.”
“It wasn’t my secret,” I pleaded.
“I suppose that was the reason: yes, I accept that. It was a mistake, though, because you had no chance of keeping the secret. That is partly why I think it better for you to drop this kind of work and go in for private practice. You lack the first essential for a detective, my dear fellow; you can hold your tongue, but you can’t hold your face.”
I’m afraid I couldn’t hold it then. It blushed in spite of me.
“I am a light sleeper, Cassilis, as you ought to know. The telephone bell woke me some minutes before you came into the house that first night. You moved as quietly as a mouse as soon as you heard it, but you see I was listening before it rang the second time and I had heard you come up to the front door and open it.”
How silly all my precautions seemed now! My chief rubbed it into me with a touch of good humour.
“I gave you a hint that you might as well make a clean breast of it at once, but you didn’t take it. When you came in to me with Charles’s message your face showed me that you had something more on your mind than having gone out without letting me know. And you gave yourself away when you told me that you had been taken to the Domino Club by a Captain Smethwick. There is no such name in the Army List.”