“Yes,” said Syme very seriously, “a promise. I swore before God that I would not tell your secret to the police. Will you swear by Humanity, or whatever beastly thing you believe in, that you will not tell my secret to the anarchists?”
“Your secret?” asked the staring Gregory. “Have you got a secret?”
“Yes,” said Syme, “I have a secret.” Then after a pause, “Will you swear?”
Gregory glared at him gravely for a few moments, and then said abruptly—
“You must have bewitched me, but I feel a furious curiosity about you. Yes, I will swear not to tell the anarchists anything you tell me. But look sharp, for they will be here in a couple of minutes.”
Syme rose slowly to his feet and thrust his long, white hands into his long, grey trousers’ pockets. Almost as he did so there came five knocks on the outer grating, proclaiming the arrival of the first of the conspirators.
“Well,” said Syme slowly, “I don’t know how to tell you the truth more shortly than by saying that your expedient of dressing up as an aimless poet is not confined to you or your President. We have known the dodge for some time at Scotland Yard.”
Gregory tried to spring up straight, but he swayed thrice.
“What do you say?” he asked in an inhuman voice.
“Yes,” said Syme simply, “I am a police detective. But I think I hear your friends coming.”