The two girls drifted swiftly along. In front of them, at the corner of the lake, near the road, was a mossy boat–house under a walnut tree, and a little landing–stage where a boat was moored, wavering like a shadow on the still grey water, below the green, decayed poles. All was shadowy with coming summer.

Suddenly, from the boat–house, a white figure ran out, frightening in its swift sharp transit, across the old landing–stage. It launched in a white arc through the air, there was a bursting of the water, and among the smooth ripples a swimmer was making out to space, in a centre of faintly heaving motion. The whole otherworld, wet and remote, he had to himself. He could move into the pure translucency of the grey, uncreated water.

Gudrun stood by the stone wall, watching.

‘How I envy him,’ she said, in low, desirous tones.

‘Ugh!’ shivered Ursula. ‘So cold!’

‘Yes, but how good, how really fine, to swim out there!’ The sisters stood watching the swimmer move further into the grey, moist, full space of the water, pulsing with his own small, invading motion, and arched over with mist and dim woods.

‘Don’t you wish it were you?’ asked Gudrun, looking at Ursula.

‘I do,’ said Ursula. ‘But I’m not sure—it’s so wet.’

‘No,’ said said Gudrun, reluctantly. She stood watching the motion on the bosom of the water, as if fascinated. He, having swum a certain distance, turned round and was swimming on his back, looking along the water at the two girls by the wall. In the faint wash of motion, they could see his ruddy face, and could feel him watching them.

‘It is Gerald Crich,’ said Ursula.

‘I know,’ replied Gudrun.

And she stood motionless gazing over the water at the face which washed up and down on the flood, as he swam steadily. From his separate element he saw them and he exulted to himself because of his own advantage, his possession of a world to himself. He was immune and perfect. He loved his own vigorous, thrusting motion, and the violent impulse of the very cold water against his limbs, buoying him up. He could see the girls watching him a way off, outside, and that pleased him. He lifted his arm from the water, in a sign to them.

‘He is waving,’ said Ursula.

‘Yes,’ replied Gudrun. They watched him. He waved again, with a strange movement of recognition across the difference.

‘Like a Nibelung,’ laughed Ursula. Gudrun said nothing, only stood still looking over the water.

Gerald suddenly turned, and was swimming away swiftly, with a side stroke. He was alone now, alone and immune in the middle of the waters, which he had all to himself. He exulted in his isolation in the new element, unquestioned and unconditioned. He was happy, thrusting with his legs and all his body, without bond or connection anywhere, just himself in the watery world.

Gudrun envied him almost painfully. Even this momentary possession of pure isolation and fluidity seemed to her so terribly desirable that she felt herself as if damned, out there on the high–road.

“Mean? Why, it means that the writer was going to put the female name Rachel, but was disturbed before he or she had time to finish. You mark my words, when this case comes to be cleared up, you will find that a woman named Rachel has something to do with it. It’s all very well for you to laugh, Mr. Sherlock Holmes. You may be very smart and clever, but the old hound is the best, when all is said and done.”

“I really beg your pardon!” said my companion, who had ruffled the little man’s temper by bursting into an explosion of laughter. “You certainly have the credit of being the first of us to find this out and, as you say, it bears every mark of having been written by the other participant in last night’s mystery. I have not had time to examine this room yet, but with your permission I shall do so now.”

As he spoke, he whipped a tape measure and a large round magnifying glass from his pocket. With these two implements he trotted noiselessly about the room, sometimes stopping, occasionally kneeling, and once lying flat upon his face. So engrossed was he with his occupation that he appeared to have forgotten our presence, for he chattered away to himself under his breath the whole time, keeping up a running fire of exclamations, groans, whistles, and little cries suggestive of encouragement and of hope. As I watched him I was irresistibly reminded of a pure-blooded, well-trained foxhound, as it dashes backward and forward through the covert, whining in its eagerness, until it comes across the lost scent. For twenty minutes or more he continued his researches, measuring with the most exact care the distance between marks which were entirely invisible to me, and occasionally applying his tape to the walls in an equally incomprehensible manner. In one place he gathered up very carefully a little pile of gray dust from the floor, and packed it away in an envelope. Finally he examined with his glass the word upon the wall, going over every letter of it with the most minute exactness. This done, he appeared to be satisfied, for he replaced his tape and his glass in his pocket.

“They say that genius is an infinite capacity for taking pains,” he remarked with a smile. “It’s a very bad definition, but it does apply to detective work.”

Gregson and Lestrade had watched the manoeuvres of their amateur companion with considerable curiosity and some contempt. They evidently failed to appreciate the fact, which I had begun to realize, that Sherlock Holmes’s smallest actions were all directed towards some definite and practical end.

“What do you think of it, sir?” they both asked.

“It would be robbing you of the credit of the case if I were to presume to help you,” remarked my friend. “You are doing so well now that it would be a pity for anyone to interfere.” There was a world of sarcasm in his voice as he spoke. “If you will let me know how your investigations go,” he continued, “I shall be happy to give you any help I can. In the meantime I should like to speak to the constable who found the body. Can you give me his name and address?”