"'I have only known Mr. Knopf a very little while,' he explained to the detectives. 'He sold me two or three stones once or twice, I think; but we are both single men, and we have often dined together. Last night he dined with me. He had that afternoon received a very fine consignment of Brazilian diamonds, as he told me, and knowing how beset I am with callers at my business place, he had brought the stones with him, hoping, perhaps, to do a bit of trade over the nuts and wine.
"'I bought £25,000 worth of him,' added the jeweller, as if he were speaking of so many farthings, 'and gave him a cheque across the dinner table for that amount. I think we were both pleased with our bargain, and we had a final bottle of '48 port over it together. Mr. Knopf left me at about 9.30, for he knows I go very early to bed, and I took my new stock upstairs with me, and locked it up in the safe. I certainly heard nothing of the noise in the mews last night. I sleep on the second floor, in the front of the house, and this is the first I have heard of poor Mr. Knopf's loss—'
"At this point of his narrative Mr. Shipman very suddenly paused, and his face became very pale. With a hasty word of excuse he unceremoniously left the room, and the detective heard him running quickly upstairs.
"Less than two minutes later Mr. Shipman returned. There was no need for him to speak; both the detective and the inspector guessed the truth in a moment by the look upon his face.
"'The diamonds!' he gasped. 'I have been robbed.'"
CHAPTER V
A NIGHT'S ADVENTURE
"Now I must tell you," continued the man in the corner, "that after I had read the account of the double robbery, which appeared in the early afternoon papers, I set to work and had a good think—yes!" he added with a smile, noting Polly's look at the bit of string, on which he was still at work, "yes! aided by this small adjunct to continued thought—I made notes as to how I should proceed to discover the clever thief, who had carried off a small fortune in a single night. Of course, my methods are not those of a London detective; he has his own way of going to work. The one who was conducting this case questioned the unfortunate jeweller very closely about his servants and his household generally.
"'I have three servants,' explained Mr. Shipman, two of whom have been with me for many years; one, the housemaid, is a fairly new comer—she has been here about six months. She came recommended by a friend, and bore an excellent character. She and the parlourmaid room together. The cook, who knew me when I was a schoolboy, sleeps alone; all three servants sleep on the floor above. I locked the jewels up in the safe which stands in the dressing-room. My keys and watch I placed, as usual, beside my bed. As a rule, I am a fairly light sleeper.