"I congratulate you. I liked her looks. And that grey dress. A nice comfortable sort of woman."

"You fool, that's her mother."

"Oh, I beg your pardon. But anyhow, Bill, I want you more than she does just now. So try and put up with me."

"I say, do you really?" said Bill, rather flattered. He had a great admiration for Antony, and was very proud to be liked by him.

"Yes. You see, things are going to happen here soon."

"Inquests and that sort of thing?"

"Well, perhaps something before that. Hallo, here comes Cayley."

Cayley was walking across the lawn towards them, a big, heavy-shouldered man, with one of those strong, clean-shaven, ugly faces which can never quite be called plain. "Bad luck on Cayley," said Bill. "I say, ought I to tell him how sorry I am and all that sort of thing? It seems so dashed inadequate."

"I shouldn't bother," said Antony.

Cayley nodded as he came to them, and stood there for a moment.

"We can make room for you," said Bill, getting up.

"Oh, don't bother, thanks. I just came to say," he went on to Antony, "that naturally they've rather lost their heads in the kitchen, and dinner won't be till half-past eight. Do just as you like about dressing, of course. And what about your luggage?"

"I thought Bill and I would walk over to the inn directly, and see about it."

"The car can go and fetch it as soon as it comes back from the station."

"It's very good of you, but I shall have to go over myself, anyhow, to pack up and pay my bill. Besides, it's a good evening for a walk. If you wouldn't mind it, Bill?"

"I should love it."

"Well, then, if you leave the bag there, I'll send the car round for it later."

"Thanks very much."

Having said what he wanted to say, Cayley remained there a little awkwardly, as if not sure whether to go or to stay. Antony wondered whether he wanted to talk about the afternoon's happenings, or whether it was the one subject he wished to avoid. To break the silence he asked carelessly if the Inspector had gone.

Cayley nodded. Then he said abruptly, "He's getting a warrant for Mark's arrest."

Bill made a suitably sympathetic noise, and Antony said with a shrug of the shoulders, "Well, he was bound to do that, wasn't he? It doesn't follow that-well, it doesn't mean anything. They naturally want to get hold of your cousin, innocent or guilty."

"Which do you think he is, Mr. Gillingham?" said Cayley, looking at him steadily.

"Mark? It's absurd," said Bill impetuously.

"Bill's loyal, you see, Mr. Cayley."

"And you owe no loyalty to anyone concerned?"

"Exactly. So perhaps I might be too frank."

Bill had dropped down on the gra.s.s, and Cayley took his place on the seat, and sat there heavily, his elbows on his knees, his chin on his hands, gazing at the ground.

"I want you to be quite frank," he said at last. "Naturally I am prejudiced where Mark is concerned. So I want to know how my suggestion strikes you who have no prejudices either way."

"Your suggestion?"

"My theory that, if Mark killed his brother, it was purely accidental as I told the Inspector."

Bill looked up with interest.

"You mean that Robert did the hold-up business," he said, "and there was a bit of a struggle, and the revolver went off, and then Mark lost his head and bolted? That sort of idea?"

"Exactly."

"Well, that seems all right." He turned to Antony. "There's nothing wrong with that, is there? It's the most natural explanation to anyone who knows Mark."

Antony pulled at his pipe.

"I suppose it is," he said slowly. "But there's one thing that worries me rather."

"What's that?" Bill and Cayley asked the question simultaneously.

"The key."

"The key?" said Bill.

Cayley lifted his head and looked at Antony. "What about the key?" he asked.

"Well, there may be nothing in it; I just wondered. Suppose Robert was killed as you say, and suppose Mark lost his head and thought of nothing but getting away before anyone could see him. Well, very likely he'd lock the door and put the key in his pocket. He'd do it without thinking, just to gain a moment's time."

"Yes, that's what I suggest."

"It seems sound enough," said Bill. "Sort of thing you'd do without thinking. Besides, if you are going to run away, it gives you more of a chance."

"Yes, that's all right if the key is there. But suppose it isn't there?"

The suggestion, made as if it were already an established fact, startled them both. They looked at him wonderingly.

"What do you mean?" said Cayley.

"Well, it's just a question of where people happen to keep their keys. You go up to your bedroom, and perhaps you like to lock your door in case anybody comes wandering in when you've only got one sock and a pair of braces on. Well, that's natural enough. And if you look round the bedrooms of almost any house, you'll find the keys all ready, so that you can lock yourself in at a moment's notice. But downstairs people don't lock themselves in. It's really never done at all. Bill, for instance, has never locked himself into the dining-room in order to be alone with the sherry. On the other hand, all women, and particularly servants, have a horror of burglars. And if a burglar gets in by the window, they like to limit his activities to that particular room. So they keep the, keys on the outside of the doors, and lock the doors when they go to bed." He knocked the ashes out of his pipe, and added, "At least, my mother always used to."

"You mean," said Bill excitedly, "that the key was on the outside of the door when Mark went into the room?"

"Well, I was just wondering."

"Have you noticed the other rooms--the billiard-room, and library, and so on?" said Cayley.