"Of course," murmured Tommy, "I saw at once where the hitch in this particular case lay, and just where the police were going astray."

"Yes?" said Tuppence eagerly.

Tommy shook his head sadly.

"I wish I did. Tuppence, it's dead easy being the Old Man in the Corner up to a certain point. But the solution beats me. Who did murder the beggar? I don't know."

He took some more newspaper cuttings out of his pocket.

"Further exhibits. Mr. Hollaby. His son. Mrs. Sessle. Doris Evans."

Tuppence pounced on the last, and looked at it for some time.

"She didn't murder him anyway," she remarked at last. "Not with a hat pin."

"Why this certainty?"

"A Lady Molly touch. She's got bobbed hair. Only one woman in twenty uses hat pins nowadays, anyway-long hair or short. Hats fit tight and pull on-there's no need for such a thing."

"Still, she might have had one by her."

"My dear boy, we don't keep them as heirlooms! What on earth should she have brought a hat pin down to Sunningdale for?"

"Then it must have been the other woman, the woman in brown."

"I wish she hadn't been tall. Then she could have been the wife. I always suspect wives who are away at the time and so couldn't have had anything to do with it. If she found her husband carrying on with that girl, it would be quite natural for her to go for him with a hat pin."

"I shall have to be careful, I see," remarked Tommy.

But Tuppence was deep in thought and refused to be drawn.

"What were the Sessles like?" she asked suddenly. "What sort of thing did people say about them?"

"As far as I can make out, they were very popular. He and his wife were supposed to be devoted to one another. That's what makes the business of the girl so odd. It's the last thing you'd have expected of a man like Sessle. He was an ex-soldier, you know. Came into a good bit of money, retired and went into this Insurance business. The last man in the world, apparently, whom you would have suspected of being a crook."

"Is it absolutely certain that he was the crook? Couldn't it have been the other two who took the money?"

"The Hollabys? They say they're ruined."

"Oh, they say! Perhaps they've got it all in a Bank under another name. I put it foolishly, I daresay, but you know what I mean. Suppose they'd been speculating with the money for some time, unbeknownst to Sessle, and lost it all. It might be jolly convenient for them that Sessle died just when he did."

Tommy tapped the photograph of Mr. Hollaby senior with his finger nail.

"So you're accusing this respectable gentleman of murdering his friend and partner? You forget that he parted from Sessle on the links in full view of Barnard and Lecky, and spent the evening in the Dormy House. Besides, there's the hat pin."

"Bother the hat pin," said Tuppence impatiently. "That hat pin, you think, points to the crime having been committed by a woman?"

"Naturally. Don't you agree?"

"No. Men are notoriously old fashioned. It takes them ages to rid themselves of preconceived ideas. They associate hat pins and hairpins with the female sex, and call them 'women's weapons.' They may have been in the past, but they're both rather out of date now. Why, I haven't had a hat pin or hairpin for the last four years."

"Then you think-?"

"That it was a man killed Sessle. The hat pin was used to make it seem a woman's crime."

"There's something in what you say, Tuppence," said Tommy slowly. "It's extraordinary how things seem to straighten themselves out when you talk a thing over."

Tuppence nodded.

"Everything must be logical-if you look at it the right way. And remember what Marriot once said about the Amateur point of view-that it had the intimacy. We know something about people like Captain Sessle and his wife. We know what they're likely to do-and what they're not likely to do. And we've each got our special knowledge."

Tommy smiled.

"You mean," he said, "that you are an authority on what people with bobbed and shingled heads are likely to have in their possession, and that you have an intimate acquaintance with what wives are likely to feel and do?"

"Something of the sort."

"And what about me? What is my special knowledge? Do husbands pick up girls etc.?"

"No," said Tuppence gravely. "You know the course you've been on it-not as a detective, searching for clues, but as a golfer. You know about golf, and what's likely to put a man off his game."

"It must have been something pretty serious to put Sessle off his game. His handicap's two, and from the seventh tee on he played like a child, so they say."

"Who say?"

"Barnard and Lecky. They were playing just behind him, you remember."

"That was after he met the woman-the tall woman in brown. They saw him speaking to her, didn't they?"

"Yes-at least-"

Tommy broke off. Tuppence looked up at him, and was puzzled. He was staring at the piece of string in his fingers, but staring with the eyes of one who sees something very different.

"Tommy-what is it?"

"Be quiet, Tuppence. I'm playing the sixth hole at Sunningdale. Sessle and old Hollaby are holding out on the sixth green ahead of me. It's getting dusk, but I can see that bright blue coat of Sessle's clearly enough. And on the footpath to the left of me there's a woman coming along. She hasn't crossed from the Ladies' Course-that's on the right-I should have seen her if she had done so. And it's odd I didn't see her on the footpath before-from the fifth tee, for instance."

He paused.

"You said just now I knew the course, Tuppence. Just behind the sixth tee, there's a little hut or shelter made of turf. Anyone could wait in there until-the right moment came. They could change their appearance there. I mean-tell me, Tuppence this is where your special knowledge comes in again-would it be very difficult for a man to look like a woman, and then change back to being a man again? Could he wear a skirt over plus fours, for instance?"

"Certainly he could. The woman would look a bit bulky, that would be all. A longish brown skirt, say, a brown sweater of the kind both men and women wear, and a woman's felt hat with a bunch of side curls attached each side. That would be all that was needed-I'm speaking, of course, of what would pass at a distance, which I take to be what you are driving at. Switch off the skirt, take off the hat and curls, and put on a man's cap which you can carry rolled up in your hand, and there you'd be-back as a man again."

"And the time required for the transformation?"

"From woman to man, a minute and a half at the outside, probably a good deal less. The other way about would take longer, you'd have to arrange the hat and curls a bit, and the skirt would stick getting it on over the plus fours."

"That doesn't worry me. It's the time for the first that matters. As I tell you, I'm playing the sixth hole. The woman in brown has reached the seventh tee now. She crosses it and waits. Sessle in his blue coat goes towards her. They stand together a minute, and then they follow the path round the trees out of sight. Hollaby is on the tee alone. Two or three minutes pass. I'm on the green now. The man in the blue coat comes back and drives off, foozling badly. The light's getting worse. I and my partner go on. Ahead of us are those two, Sessle slicing and topping and doing everything he shouldn't do. At the eighth green, I see him stride off and vanish down the slip. What happened to him to make him play like a different man?"

"The woman in brown-or the man, if you think it was a man."

"Exactly, and where they were standing-out of sight, remember, of those coming after them-there's a deep tangle of furze bushes. You could thrust a body in there, and it would be pretty certain to lie hidden until the morning."

"Tommy! You think it was then-But someone would have heard-"

"Heard what? The doctors agreed death must have been instantaneous. I've seen men killed instantaneously in the War. They don't cry out as a rule-just a gurgle, or a moan -perhaps just a sigh, or a funny little cough. Sessle comes towards the seventh tee, and the woman comes forward and speaks to him. He recognizes her perhaps, as a man he knows masquerading. Curious to learn the why and wherefore, he allows himself to be drawn along the footpath out of sight. One stab with the deadly hat pin as they walk along. Sessle falls-dead. The other man drags his body into the furze bushes, strips off the blue coat, then sheds his own skirt and the hat and curls. He puts on Sessle's well known blue coat and cap, and strides back to the tee. Three minutes would do it. The others behind can't see his face, only the peculiar blue coat they know so well. They never doubt that it's Sessle-but he doesn't play Sessle's brand of golf. They all say he played like a different man. Of course he did. He was a different man."

"But-"

"Point No. 2. His action in bringing the girl down there was the action of a different man. It wasn't Sessle who met Doris Evans at a Cinema, and induced her to come down to Sunningdale. It was a man calling himself Sessle. Remember, Doris Evans wasn't arrested until a fortnight after the crime. She never saw the body. If she had, she might have bewildered everyone by declaring that that wasn't the man who took her out on the golf links that night, and spoke so wildly of suicide. It was a carefully laid plot. The girl invited down for Wednesday when Sessle's house would be empty, then the hat pin which pointed to its being a woman's doing. The murderer meets the girl, takes her into the Bungalow and gives her supper, then takes her out on the links and when he gets to the scene of the crime, brandishes his revolver and scares the life out of her. Once she has taken to her heels, all he has to do is to pull out the body and leave it lying on the tee. The revolver he chucks into the bushes. Then he makes a neat parcel of the skirt and hat and-now I admit I'm guessing-in all probability walks to Woking which is only about six or seven miles away, and goes back to town from there."

"Wait a minute," said Tuppence. "There's one thing you haven't explained. What about Hollaby?"