"Nobody."

"When did he arrive?" I asked.

"The night before last. He was alone--with only a handbag. I charged
him with a deposit for his room."

"Have you ever seen him before?" I asked.

"Never to my recollection."

"Neither have I," remarked the concierge. "He seemed very afraid of
being seen. I noticed him in the lounge last night. He left this
morning quite suddenly, and without taking anything--even a cup of
coffee."

"He left in a violent hurry--eh?" I exclaimed, well knowing the
reason. "Well," I added, "I wish to see the manager."

"I will inform him," the clerk replied, and he went to the telephone.
A minute later, after exchanging a few words in Spanish, he turned to
me, saying:

"You will find the manager's office on the first floor. If you take
the lift the man will direct you, senor."

A few minutes later I was seated in the office of an elderly
bald-headed man, a typical _hotelier_, courteous, smiling, and eager
to hear any complaint that I might have to make.

At once I told him of my curious adventure of the previous night, and
of the sudden flight of the mysterious stranger whom I had discovered
in my room.

"That is certainly strange, sir," he replied in English. "His excuse
was a very ingenious one, to say the least. I think we ought to inform
the police. Do you not agree?"

I told him of my discovery of the carpet pins, and asked his advice as
to whom I might send them for chemical analysis.

At once he suggested Professor Vega, of the Princesa Hospital in the
Calle Alberto Aguilera, adding:

"The Professor often dines here. If you wish, I will take you to him."

So still leaving the three carpet pins upon the little glass tray I
wrapped it in paper and together we went round to the hospital, where
I was introduced to a tall, narrow-faced, grey-haired man in a long
linen coat. To him I explained how I had found the pins on the carpet
beside my bed, and asking whether he would submit them to examination.

He looked at them critically, first with the naked eye and afterwards
by means of a large reading-glass. Then he grunted in dissatisfaction
and promised that next day, or the day after, he would tell me the
result of his analysis.

As we drove back to the hotel the manager remarked:

"It is a very curious affair, sir, to say the least. One does not
scatter carpet pins about a bedroom, and particularly when the points
are smeared with some mysterious substance. If they had be