The doctor sat down with a polite impatience on his professional perch; MacIan remained standing, but Turnbull threw himself almost with luxury into a hard wooden arm-chair.

“This is a most absurd business, Doctor,” he said, “and I am ashamed to take up the time of busy professional men with such pranks from outside.  The plain fact is, that he and I and a pack of silly men and girls have organized a game across this part of the country—­a sort of combination of hare and hounds and hide and seek—­I dare say you’ve heard of it.  We are the hares, and, seeing your high wall look so inviting, we tumbled over it, and naturally were a little startled with what we found on the other side.”

“Quite so!” said the doctor, mildly.  “I can understand that you were startled.”

Turnbull had expected him to ask what place was the headquarters of the new exhilarating game, and who were the male and female enthusiasts who had brought it to such perfection; in fact, Turnbull was busy making up these personal and topographical particulars.  As the doctor did not ask the question, he grew slightly uneasy, and risked the question:  “I hope you will accept my assurance that the thing was an accident and that no intrusion was meant.”

“Oh, yes, sir,” replied the doctor, smiling, “I accept everything that you say.”

“In that case,” said Turnbull, rising genially, “we must not further interrupt your important duties.  I suppose there will be someone to let us out?”

“No,” said the doctor, still smiling steadily and pleasantly, “there will be no one to let you out.”

“Can we let ourselves out, then?” asked Turnbull, in some surprise.

“Why, of course not,” said the beaming scientist; “think how dangerous that would be in a place like this.”

“Then, how the devil are we to get out?” cried Turnbull, losing his manners for the first time.

“It is a question of time, of receptivity, and treatment,” said the doctor, arching his eyebrows indifferently.  “I do not regard either of your cases as incurable.”

And with that the man of the world was struck dumb, and, as in all intolerable moments, the word was with the unworldly.

MacIan took one stride to the table, leant across it, and said:  “We can’t stop here, we’re not mad people!”

“We don’t use the crude phrase,” said the doctor, smiling at his patent-leather boots.

“But you can’t think us mad,” thundered MacIan.  “You never saw us before.  You know nothing about us.  You haven’t even examined us.”

The doctor threw back his head and beard.  “Oh, yes,” he said, “very thoroughly.”

“But you can’t shut a man up on your mere impressions without documents or certificates or anything?”

The doctor got languidly to his feet.  “Quite so,” he said.  “You certainly ought to see the documents.”

He went across to the curious mock book-shelves and took down one of the flat mahogany cases.  This he opened with a curious key at his watch-chain, and laying back a flap revealed a quire of foolscap covered with close but quite clear writing.  The first three words were in such large copy-book hand that they caught the eye even at a distance.  They were:  “MacIan, Evan Stuart.”