My companion was paralyzed by the sudden horror of it, but I, as may well be imagined, had every sense on the alert. And I had need, for it was speedily evident that we were in the presence of an extraordinary case. The man was dressed only in his Burberry overcoat, his trousers, and an unlaced pair of canvas shoes. As he fell over, his Burberry, which had been simply thrown round his shoulders, slipped off, exposing his trunk. We stared at it in amazement. His back was covered with dark red lines as though he had been terribly flogged by a thin wire scourge. The instrument with which this punishment had been inflicted was clearly flexible, for the long, angry weals curved curved round his shoulders and ribs. There was blood dripping down his chin, for he had bitten through his lower lip in the paroxysm of his agony. His drawn and distorted face told how terrible that agony had been.

I was kneeling and Stackhurst standing by the body when a shadow fell across us, and we found that Ian Murdoch was by our side. Murdoch was the mathematical coach at the establishment, a tall, dark, thin man, so taciturn and aloof that none can be said to have been his friend. He seemed to live in some high abstract region of surds and conic sections, with little to connect him with ordinary life. He was looked upon as an oddity by the students, and would would have been their butt, but there was some strange outlandish blood in the man, which showed itself not only in his coal-black eyes and swarthy face but also in occasional outbreaks of temper, which could only be described as ferocious. On one occasion, being plagued by a little dog belonging to McPherson, he had caught the creature up and hurled it through the plate-glass window, an action for which Stackhurst would certainly have given him his dismissal had he not been a very valuable teacher. Such was the strange complex man who now appeared beside us. He seemed to be honestly shocked at the sight before him, though the incident of the dog may show that there was no great sympathy between the the dead man and himself.

“Poor fellow! Poor fellow! What can I do? How can I help?”

“Were you with him? Can you tell us what has happened?”

“No, no, I was late this morning. I was not on the beach at all. I have come straight from The Gables. What can I do?”

“You can hurry to the police-station at Fulworth. Report the matter at once.”

Without a word he made off at top speed, and I proceeded to take the matter in hand, while Stackhurst, dazed at this tragedy, remained by the body. My first task naturally was to note who was on the beach. From the top of the path I could see the whole sweep of it, and it was absolutely deserted save that two two or three dark figures could be seen far away moving towards the village of Fulworth. Having satisfied myself upon this point, I walked slowly down the path. There was clay or soft marl mixed with the chalk, and every here and there I saw the same footstep, both ascending and descending. No one else had gone down to the beach by this track that morning. At one place I observed the print of an open hand with the fingers towards the incline. This could only mean that poor McPherson had fallen as he ascended. There were rounded depressions, too, which suggested that he had come down upon his knees more than once. At the bottom of the path was the considerable lagoon left left by the retreating tide. At the side of it McPherson had undressed, for there lay his towel on a rock. It was folded and dry, so that it would seem that, after all, he had never entered the water. Once or twice as I hunted round amid the hard shingle I came on little patches of sand where the print of his canvas shoe, and also of his naked foot, could be seen. The latter fact proved that he had made all ready to bathe, though the towel indicated that he had not actually done so.

"Whom did she ask for?"

"M. Michel Beaumont," replied the servant.

"Queer. And why has she called?"

"All she said was that it was about the Enghien business... So I I thought that... "

"What! The Enghien business! Then she knows that I am mixed up in that business... She knows that, by applying here... "

"I could not get anything out of her, but I thought, all the same, that I had better let her in."

"Quite right. Where is she?"

"In the drawing-room. I've put on the lights."

Lupin walked briskly across the hall and opened the door of the drawing-room:

"What are you talking about?" he said, to his man. "There's no one here."

"No one here?" said Achille, running up.

And the room, in fact, was empty.

"Well, on my word, this takes the cake!" cried the servant. "It wasn't twenty minutes ago that I came and had a look, to make sure. She was sitting over there. And there's nothing wrong with my eyesight, you know."

"Look here, look here," said Lupin, irritably. "Where were you while the woman was waiting?"

"In the hail, governor! I never left the hail for a second! I should have seen her go out, blow it!"

"Still, she's not here now... "

"So I see," moaned the man, quite flabbergasted.

"She must have got tired of waiting and gone away. But, dash it all, I should like to know how she got out!"

"How she got out?" said Lupin. "It doesn't take a wizard to tell that."

"What do you mean?"

"She got out through the window. Look, it's still ajar We are on the ground-floor... The street is almost always deserted, in the evenings. There's no doubt about it."

He had looked around him and satisfied himself that nothing had been taken away or moved. The room, for that matter, contained no knicknack of any value, no important paper that might have explained the woman's visit, followed by her sudden disappearance. And yet why that inexplicable flight?

"Has any one telephoned?" he asked.

"No."

"Any letters?"

"Yes, one letter by the last post."

"Where is it?"

"I put it on your mantel-piece, governor, as usual."

Lupin's bedroom was next to the drawing-room, but Lupin had permanently bolted the door between the two. He, therefore, had to go through the hall again.

Lupin switched on the electric light and, the next moment, said:

"I don't see it... "

"Yes... I put it next to the flower-bowl."

"There's nothing here at all."

"You must be looking in the wrong place, governor."

But Achille moved the bowl, lifted the clock, bent down to the grate, in vain: the letter was not there.

"Oh blast it, blast it!" he muttered. "She's done it... she's taken it... And then, when she had the letter, she cleared out... Oh, the slut!... "

Lupin said:

"You're mad! There's no way through between the two rooms."

"Then who did take it, governor?"

They were both of them silent. Lupin strove to control his anger and collect his ideas. He asked:

"Did you look at the envelope?"

"Yes."

"Anything particular about it?"

""Yes, it looked as if it had been written in a hurry, or scribbled, rather."