The instant I saw it I closed my hand and hid it from view.
Then I glanced furtively around, and seeing that my action had been unobserved I quickly transferred it to my vest pocket, covering the movement by taking out my watch to glance at it.
I confess that my heart beat quickly, and in all probability the colour at that moment had left my face, for I had, by sheer accident, discovered a clue.
To examine it there was impossible, for of such a character was it that I had no intention, as yet, to arouse the suspicions of the police. I intended at the earliest moment to apprise my friend, Ambler Jevons, of the facts and with him pursue an entirely independent inquiry.
Scarcely had I safely pocketed the little object I had picked up from where the murderer must have stood when the inspector went out upon the landing and called to the constable in the hall:
"Four-sixty-two, lock that door and come up here a moment."
"Yes, sir," answered a gruff voice from below, and in a few moments the constable entered, closing the door after him.
"How many times have you passed this house on your beat to-night, four-sixty-two?" inquired the inspector.
"About eight, sir. My beat's along the Richmond Road, from the Lion Gate down to the museum, and then around the back streets."
"I saw a man come out of this house hurriedly, soon after I came on duty. I was standing on the opposite side, under the wall of the Gardens. The lady what's downstairs let him out and told him to fetch the doctor quickly."
"Where is he?" asked the inspector, while the detective with the ready note-book scribbled down the name.
"He came to fetch me, and Miss Mivart has now sent him to fetch her sister. He was the first to make the discovery."
"Oh, was he?" exclaimed the detective-sergeant, with some suspicion. "It's rather a pity that he's been sent out again. He might be able to tell us something."
"He'll be back in an hour, I should think."
"Yes, but every hour is of consequence in a matter of this sort," remarked the sergeant. "Look here, Davidson," he added, turning to one of the plain-clothes men, "just go round to the station and send a wire to the Yard, asking for extra assistance. Give them a brief outline of the case. They'll probably send down Franks or Moreland. If I'm not mistaken, there's a good deal more in this mystery than meets the eye."