“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 been there before you retired to bed the chambermaid must certainly have seen them. She makes a round of the rooms each night at ten o’clock. Besides, the facts that the bolt had been tampered with, and also that the man who occupied 175 left so early and so hurriedly, are additionally suspicious. Yes,” he added, “I think we ought to see the police.”

With that object he took me at once to Señor Andrade, the Chief of Police, a short, stout, alert little man, who heard me with keen interest and seemed very puzzled.

“The intruder’s explanation was certainly a very clever one,” he remarked in French. “It is a pity you did not demand to see his friend, Pedro Espada. If you had, you would have discovered him to be nonexistent.”