“The interval between Wednesday and Saturday was a time of anxious thought and considerable excitement.  I went out every night, and had the pleasure of discovering that I was honored by the attendance—­at a little distance—­of Mr. Piragoff.  One evening only I eluded him, and watched him drive off furiously in a hansom in pursuit of another hansom which was supposed to contain me.  On that night I visited the museum.  Not that I had anything special to do.  My very complete and even elaborate arrangements had been made some time before and I now had only to look them over and see that they were in going order; to test, for instance, the brass handle that was connected with the electric main, and see that the well-oiled blocks of a couple of purchase tackles ran smoothly and silently.  Everything was in working trim, even to the concussor, stowed out of sight, but within easy reach, in its narrow basket.

“Saturday night arrived in due course.  I shut up the shop at nine, put on evening clothes, took the newly-purchased Gladstone and hailed a hansom.  I drove, in the first place, to the Criterion Restaurant and dined delicately but substantially, carefully avoiding indigestible dishes.  From the restaurant I drove to the museum, where I loitered, making a final inspection of my arrangements, until twenty-five minutes past twelve.  Then I came forth and walked quietly to Upper Bedford Place.

“As I turned the corner and looked down the wide thoroughfare the long stretch of pavement contained but a single figure; a dim, dark blot on the gray of the summer night.  It moved towards me, and, resolving itself into a definite shape, showed me Piragoff in evening dress, enveloped in a voluminous overcoat and carrying a small hand-bag.

“‘You are punctual, Vosper,’ he said graciously.  ’Shall we make our visit now?  Is the house quiet yet?  These are not, you see.’  He nodded at the boarding-houses that we were passing, several of which still showed lights in the windows.

“‘Our house has settled down,’ I answered.  ’The collector is an early bird.  I have just been past it to see that all the lights were out.’

“We walked quickly across the square towards the neighborhood of my house.  Piragoff was very affable.  He conversed cheerfully as we went and gave a pleasant ‘Good night’ to a policeman, who touched his helmet civilly in response.  When I halted at the door of the museum, he looked about him with a slight frown.

“‘I seem to know this place,’ he murmured.  ’Yes, I have been here before; many years ago.  Yes, yes; I remember.’

“He laughed softly as if recalling an amusing incident.  I set my teeth, inserted the key and pushed the door open.

“‘Enter,’ I said.  He stepped into the hall.  I followed and softly closed the door, slipping up the catch as the lock clicked.  It was a small precaution, but enough to hinder a hasty retreat.

“I piloted him through to the museum and switched on a single electric lamp which filled the great room with a ghostly twilight.  Piragoff looked about him inquisitively and his eye fell on the long wall-case with the dimly-seen, pallid shapes of the company within it.  His face blanched suddenly and he stared with wide-open eyes.