"What's that?" I cried.
"Ma foi!" retorted Poirot. "It sounds very like your 'unexpected guest' in my bedroom."
"But how can any one be in there?
There's no door except into this room." "Your memory is excellent, Hastings. Now for the deductions."
"The window!
But it's a burglar, then?
He must have had a stiff climb of it - I should say it was almost impossible."
I had risen to my feet and was striding in the direction of the door when the sound of a fumbling at the handle from the other side arrested me.
The door swung slowly open.
Framed in the doorway stood a man.
He was coated from head to foot with dust and mud; his face was thin and emaciated.
He stared at us for a moment, and then swayed and fell.
Poirot hurried to his side, then he looked up and spoke to me.
"Brandy - quickly."
I dashed some brandy into a glass and brought it.
Poirot managed to administer a little, and together we raised him and carried him to the couch.
In a few minutes he opened his eyes and looked round him with an almost vacant stare.
"What is it you want, monsieur?" said Poirot.
The man opened his lips and spoke in a queer mechanical voice.
"M. Hercule Poirot, 14 Farraway Street."
"Yes, yes; I am he."
The man did not seem to understand, and merely repeated in exactly the same tone:
"M. Hercule Poirot, 14 Farraway Street."
Poirot tried him with several questions.
Sometimes the man did not answer at all; sometimes he repeated the same phrase.
Poirot made a sign to me to ring up on the telephone.
"Get Dr. Ridgeway to come round."
The doctor was in luckily; and as his house was only just round the corner, few minutes elapsed before he came bustling in. "What's all this, eh?"
Poirot gave a brief explanation, and the doctor started examining our strange visitor, who seemed quite unconscious of his presence or ours.
"H'm!" said Dr. Ridgeway, when he had finished. "Curious case."
"Brain fever?" I suggested.
The doctor immediately snorted with contempt.
"Brain fever!
Brain fever!
No such thing as brain fever.
An invention of novelists.
No; the man's had a shock of some kind.
He's come here under the force of a persistent idea - to find M. Hercule Poirot, 14 Farraway Street - and he repeats those words mechanically without in the least knowing what they mean."
"Aphasia?" I said eagerly.
This suggestion did not cause the doctor to snort quite as violently as my last one had done.
He made no answer, but handed the man a sheet of paper and a pencil.
"Let's see what he'll do with that," he remarked.
The man did nothing with it for some moments, then he suddenly began to write feverishly.
With equal suddenness he stopped and let both paper and pencil fall to the ground.
The doctor picked it up, and shook his head.
"Nothing here.
Only the figure 4 scrawled a dozen times, each one bigger than the last.
Wants to write 14 Farraway Street, I expect.
It's an interesting case - very interesting.
Can you possibly keep him here until this afternoon?