Brotherson surveyed him with an irony which conveyed a very different message to the detective than any he had intended.  Then quickly: 

“To how many have you spoken, dilating upon this device, and publishing abroad my secret?”

“I have spoken to no one, not even to Mr. Gryce.  That shows my honesty as nothing else can.”

“You have kept my secret intact?”

“Entirely so, sir.”

“So that no one, here or elsewhere, shares our knowledge of the new points in this mechanism?”

“I say so, sir.”

“Then if I should kill you,” came in ferocious accents, “now —­here—­”

“You would be the only one to own that knowledge.  But you won’t kill me.”

“Why?”

“Need I go into reasons?”

“Why?  I say.”

“Because your conscience is already too heavily laden to bear the burden of another unprovoked crime.”

Brotherson, starting back, glared with open ferocity upon the man who dared to face him with such an accusation.

“God! why didn’t I shoot you on entrance!” he cried.  “Your courage is certainly colossal.”

A fine smile, without even the hint of humour now, touched the daring detective’s lip.  Brotherson’s anger seemed to grow under it, and he loudly repeated: 

“It’s more than colossal; it’s abnormal and—­” A moment’s pause, then with ironic pauses—­“and quite unnecessary save as a matter of display, unless you think you need it to sustain you through the ordeal you are courting.  You wish to help me finish and prepare for flight?”

“I sincerely do.”

“You consider yourself competent?”

“I do.”

Brotherson’s eyes fell and he walked once to the extremity of the oval flooring and back.

“Well, we will grant that.  But that’s not all that is necessary.  My requirements demand a companion in my first flight.  Will you go up in the car with me on Saturday night?”

A quick affirmative was on Sweetwater’s lips but the glimpse which he got of the speaker’s face glowering upon him from the shadows into which Brotherson had withdrawn, stopped its utterance, and the silence grew heavy.  Though it may not have lasted long by the clock, the instant of breathless contemplation of each other’s features across the intervening space was of incalculable moment to Sweetwater, and, possibly, to Brotherson.  As drowning men are said to live over their whole history between their first plunge and their final rise to light and air, so through the mind of the detective rushed the memories of his past and the fast fading glories of his future; and rebelling at the subtle peril he saw in that sardonic eye, he vociferated an impulsive: 

“No!  I’ll not—­” and paused, caught by a new and irresistible sensation.

A breath of wind—­the first he had felt that night—­had swept in through some crevice in the curving wall, flapping the canvas enveloping the great car.  It acted like a peal to battle.  After all, a man must take some risks in his life, and his heart was in this trial of a redoubtable mechanism in which he had full faith.  He could not say no to the prospect of being the first to share a triumph which would send his name to the ends of the earth; and, changing the trend of his sentence, he repeated with a calmness which had the force of a great decision.