But no one heeded.  The new arrival munches his roll and waits impatiently for his coffee, while without, the clouds pile soundlessly in the sky, one of them taking the form of a huge hand with clutching fingers reaching down into the hollow void beneath.

XLI

AT SIX

Mr. Challoner had been honest in his statement regarding the departure of Sweetwater.  He had not only paid and dismissed our young detective, but he had seen him take the train for New York.  And Sweetwater had gone away in good faith, too, possibly with his convictions undisturbed, but acknowledging at last that he had reached the end of his resources.  But the brain does not loose its hold upon its work as readily as the hand does.  He was halfway to New York and had consciously bidden farewell to the whole subject, when he suddenly startled those about him by rising impetuously to his feet.  He sat again immediately, but with a light in his small grey eye which Mr. Gryce would have understood and revelled in.  The idea for which he had searched industriously for months had come at last, unbidden; thrown up from some remote recess of the mind which had seemingly closed upon the subject forever.

“I have it.  I have it,” he murmured in ceaseless reiteration to himself.  “I will go back to Mr. Challoner and let him decide if the idea is worth pursuing.  Perhaps an experiment may be necessary.  It was bitter cold that night; I wish it were icy weather now.  But a chemist can help us out.  Good God! if this should be the explanation of the mystery, alas for Orlando and alas for Oswald!”

But his sympathies did not deter him.  He returned to Derby at once, and as soon as he dared, presented himself at the hotel and asked for Mr. Challoner.

He was amazed to find that gentleman already up and in a state of agitation that was very disquieting.  But he brightened wonderfully at sight of his visitor, and drawing him inside the room, observed with trembling eagerness: 

“I do not know why you have come back, but never was man more welcome.  Mr. Brotherson has confessed.”

“Confessed!”

“Yes, he killed both women; my daughter and his neighbour, the washerwoman, with a—­”

“Wait,” broke in Sweetwater, eagerly, “let me tell you.”  And stooping, he whispered something in the other’s ear.

Mr. Challoner stared at him amazed, then slowly nodded his head.

“How came you to think—­” he began; but Sweetwater in his great anxiety interrupted him with a quick: 

“Explanations will keep, Mr. Challoner.  What of the man himself?  Where is he?  That’s the important thing now.”

“He was in his room till early this morning writing letters, but he is not there now.  The door is unlocked and I went in.  From appearances I fear the worst.  That is why your presence relieves me so.  Where do you think he is?”