“You are out after one of the big heads of the crook world,” he said.  “He knows it and he’s trailing you.  My luck’s turned.  How can I help?”

Harley stood up, facing Mr. Brinn.  “He knows it, as you say,” he replied, “and I hold my life in my hands.  But from your answer to the question which I have come here to-night to ask you, I shall conclude whether or not your danger at the moment is greater than mine.”

“Good,” said Nicol Brinn.

In that unique room, at once library and museum, amid relics of a hundred ages, spoil of the chase, the excavator, and the scholar, these two faced each other; and despite the peaceful quiet of the apartment up to which as a soothing murmur stole the homely sounds of Piccadilly, each saw in the other’s eyes recognition of a deadly peril.  It was a queer, memorable moment.

“My question is simple but strange,” said Paul Harley.  “It is this:  What do you know of ’Fire-Tongue’?”

CHAPTER V. THE GATES OF HELL

If Paul Harley had counted upon the word “Fire-Tongue” to have a dramatic effect upon Nicol Brinn, he was not disappointed.  It was a word which must have conveyed little or nothing to the multitude and which might have been pronounced without perceptible effect at any public meeting in the land.  But Mr. Brinn, impassive though his expression remained, could not conceal the emotion which he experienced at the sound of it.  His gaunt face seemed to grow more angular and his eyes to become even less lustrous.

“Fire-Tongue!” he said, tensely, following a short silence.  “For God’s sake, when did you hear that word?”

“I heard it,” replied Harley, slowly, “to-night.”  He fixed his gaze intently upon the sallow face of the American.  “It was spoken by Sir Charles Abingdon.”

Closely as he watched Nicol Brinn while pronouncing this name he could not detect the slightest change of expression in the stoic features.

“Sir Charles Abingdon,” echoed Brinn; “and in what way is it connected with your case?”

“In this way,” answered Harley.  “It was spoken by Sir Charles a few moments before he died.”

Nicol Brinn’s drooping lids flickered rapidly.  “Before he died!  Then Sir Charles Abingdon is dead!  When did he die?”

“He died to-night and the last words that he uttered were ’Fire-Tongue’—­” He paused, never for a moment removing that fixed gaze from the other’s face.

“Go on,” prompted Mr. Brinn.

“And ‘Nicol Brinn.’”

Nicol Brinn stood still as a carven man.  Indeed, only by an added rigidity in his pose did he reward Paul Harley’s intense scrutiny.  A silence charged with drama was finally broken by the American.  “Mr. Harley,” he said, “you told me that you were up against the big proposition of your career.  You are right.”

With that he sat down in an armchair and, resting his chin in his hand, gazed fixedly into the empty grate.  His pose was that of a man who is suddenly called upon to review the course of his life and upon whose decision respecting the future that life may depend.  Paul Harley watched him in silence.