She left the room.  The moment the door closed Kennedy reached over and took one from the case.  “I have some of Lockwood’s already, but another won’t matter, as long as I can get it,” he said.  “I thought it was her father’s.  When she brings them, smoke one with me, and be careful to save the stub.  I want it.”

A moment later she entered with a metal box that must have held several hundred.  Kennedy and I each took one and lighted it, then for several minutes chatted as an excuse for staying.  As for myself, I was glad enough to leave a pretty large stub, for I did not like it.  These cigarettes, like those Whitney had offered us, had a peculiar flavour which I had not acquired a liking for.

“You must let me know whether anything else develops from the meeting in the tea room,” said Kennedy finally, rising.  “I shall be at the laboratory some time, I think.”

XIV

THE INTERFEROMETER

Norton was waiting for us at the laboratory when we returned, evidently having been there some time.

“I was on my way to my apartment,” he began, “when I thought I’d drop in to see how things are progressing.”

“Slowly,” returned Kennedy, throwing off his street clothes and getting into his laboratory togs.

“Have you seen Whitney since I had the break with him?” asked Norton, a trifle anxiously.

I wondered whether Kennedy would tell Norton what to expect from Whitney.  He did not, however.

“Yes,” he replied, “just now we had an appointment with Senora de Moche and some others and ran into him at the hotel for a few moments.”

“What did he say about me?” queried Norton.

“He hadn’t changed his mind,” evaded Kennedy.  “Have you heard anything from him?”

“Not a syllable.  The break is final.  Only I was wondering what he was telling people about me.  He’ll tell them something—­his side of the case.”

“Well,” considered Kennedy, as though racking his brain for some remark which he remembered, while Norton watched him eagerly, “I do recall that he was terribly sore about the loss of the dagger, and seemed to think that it was your fault.”

“I thought so, I knew it,” replied Norton bitterly.  “I can see it coming.  All the trustees will hear of my gross negligence in letting the Museum be robbed.  I suppose I ought to sit up there all night.  Oh, by the way, there’s another thing I wanted to ask you.  Have you ever done anything with those shoe-prints you found in the dust of the mummy case?”

I glanced at Kennedy, wondering whether he felt that the time had come to reveal what he had discovered.  He said nothing for a moment, but reached into a drawer and pulled out the papers, which I recognized.

“Here they are,” he said, picking out the original impression which he had taken.

“Yes,” repeated Norton, “but have you been able to do anything toward identifying them?”