"One of the housemaids," explained Cayley. "You didn't hear what she told the Inspector? Of course, as I told Birch, girls of that cla.s.s make things up, but he seemed to think she was genuine."

"What was it?" said Bill.

Cayley told them of what Elsie had heard through the office door that afternoon.

"You were in the library then, of course," said Antony, rather to himself than to the other. "She might have gone through the hall without your hearing."

"Oh, I've no doubt she was there, and heard voices. Perhaps heard those very words. But-" He broke off, and then added impatiently, "It was accidental. I know it was accidental. What's the good of talking as if Mark was a murderer?" Dinner was announced at that moment, and as they went in, he added, "What's the good of talking about it at all, if it comes to that?"

"What, indeed?" said Antony, and to Bill's great disappointment they talked of books and politics during the meal.

Cayley made an excuse for leaving them as soon as their cigars were alight. He had business to attend to, as was natural. Bill would look after his friend. Bill was only too willing. He offered to beat Antony at billiards, to play him at piquet, to show him the garden by moonlight, or indeed to do anything else with him that he required.

"Thank the Lord you're here," he said piously. "I couldn't have stood it alone."

"Let's go outside," suggested Antony. "It's quite warm. Somewhere where we can sit down, right away from the house. I want to talk to you."

"Good man. What about the bowling-green?"

"Oh, you were going to show me that, anyhow, weren't you? Is it somewhere where we can talk without being overheard?"

"Rather. The ideal place. You'll see."

They came out of the front door and followed the drive to the left. Coming from Waldheim, Antony had approached the house that afternoon from the other side. The way they were going now would take them out at the opposite end of the park, on the high road to Stanton, a country town some three miles away. They pa.s.sed by a gate and a gardener's lodge, which marked the limit of what auctioneers like to call "the ornamental grounds of the estate," and then the open park was before them.

"Sure we haven't missed it?" said Antony. The park lay quietly in the moonlight on either side of the drive, wearing a little way ahead of them a deceptive air of smoothness which retreated always as they advanced.

"Rum, isn't it?" said Bill. "An absurd place for a bowling green, but I suppose it was always here."

"Yes, but always where? It's short enough for golf, perhaps, but-Hallo!"

They had come to the place. The road bent round to the right, but they kept straight on over a broad gra.s.s path for twenty yards, and there in front of them was the green. A dry ditch, ten feet wide and six feet deep, surrounded it, except in the one place where the path went forward. Two or three gra.s.s steps led down to the green, on which there was a long wooden beach for the benefit of spectators.

"Yes, it hides itself very nicely," said Antony. "Where do you keep the bowls?"

"In a sort of summer house place. Round here."

They walked along the edge of the green until they came to it a low wooden bunk which had been built into one wall of the ditch.

"H'm. Jolly view."

Bill laughed.

"n.o.body sits there. It's just for keeping things out of the rain."

They finished their circuit of the green "Just in case anybody's in the ditch," said Antony and then sat down on the bench.

"Now then," said Bill, "We are alone. Fire ahead."

Antony smoked thoughtfully for a little. Then he took his pipe out of his mouth and turned to his friend.

"Are you prepared to be the complete Watson?" he asked.

"Watson?"

"Do-you-follow-me-Watson; that one. Are you prepared to have quite obvious things explained to you, to ask futile questions, to give me chances of scoring off you, to make brilliant discoveries of your own two or three days after I have made them myself all that kind of thing? Because it all helps."

"My dear Tony," said Bill delightedly, "need you ask?" Antony said nothing, and Bill went on happily to himself, "I perceive from the strawberry-mark on your shirt-front that you had strawberries for dessert. Holmes, you astonish me. Tut, tut, you know my methods. Where is the tobacco? The tobacco is in the Persian slipper. Can I leave my practice for a week? I can."

Antony smiled and went on smoking. After waiting hopefully for a minute or two, Bill said in a firm voice:

"Well then, Holmes, I feel bound to ask you if you have deduced anything. Also whom do you suspect?"

Antony began to talk.

"Do you remember," he said, "one of Holmes's little scores over Watson about the number of steps up to the Baker Street lodging? Poor old Watson had been up and down them a thousand times, but he had never thought of counting them, whereas Holmes had counted them as a matter of course, and knew that there were seventeen. And that was supposed to be the difference between observation and non-observation. Watson was crushed again, and Holmes appeared to him more amazing than ever. Now, it always seemed to me that in that matter Holmes was the a.s.s, and Watson the sensible person. What on earth is the point of keeping in your head an unnecessary fact like that? If you really want to know at any time the number of steps to your lodging, you can ring up your landlady and ask her. I've been up and down the steps of the club a thousand times, but if you asked me to tell you at this moment how many steps there are I couldn't do it. Could you?"

"I certainly couldn't," said Bill.

"But if you really wanted to know," said Antony casually, with a sudden change of voice, "I could find out for you without even bothering to ring up the hall-porter."

Bill was puzzled as to why they were talking about the club steps, but he felt it his duty to say that he did want to know how many they were.

"Right," said Antony. "I'll find out."

He closed his eyes.

"I'm walking up St James' Street," he said slowly. "Now I've come to the club and I'm going past the smoking-room-windows-one-two three four. Now I'm at the steps. I turn in and begin going up them. One-two-three-four-five-six, then a broad step; six-seven-eight-nine, another broad step; nine-ten-eleven. Eleven I'm inside. Good morning, Rogers. Fine day again." With a little start he opened his eyes and came back again to his present surroundings. He turned to Bill with a smile. "Eleven," he said. "Count them the next time you're there. Eleven and now I hope I shall forget it again."

Bill was distinctly interested.

"That's rather hot," he said. "Expound."

"Well, I can't explain it, whether it's something in the actual eye, or something in the brain, or what, but I have got rather an uncanny habit of recording things unconsciously. You know that game where you look at a tray full of small objects for three minutes, and then turn away and try to make a list of them. It means a devil of a lot of concentration for the ordinary person, if he wants to get his list complete, but in some odd way I manage to do it without concentration at all. I mean that my eyes seem to do it without the brain consciously taking any part. I could look at the tray, for instance, and talk to you about golf at the same time, and still get my list right."

"I should think that's rather a useful gift for an amateur detective. You ought to have gone into the profession before."

"Well, it is rather useful. It's rather surprising, you know, to a stranger. Let's surprise Cayley with it, shall we?"

"How?"

"Well, let's ask him-" Antony stopped and looked at Bill comically, "let's ask him what he's going to do with the key of the office."

For a moment Bill did not understand.

"Key of the office?" he said vaguely. "You don't mean-Tony! What do you mean? Good G.o.d! do you mean that Cayley-But what about Mark?"

"I don't know where Mark is-that's another thing I want to know-but I'm quite certain that he hasn't got the key of the office with him. Because Cayley's got it."