"I've only just thought about it while I've been sitting out here. You live here--haven't you ever noticed them?"

Cayley sat considering, with his head on one side.

"It seems rather absurd, you know, but I can't say that I have." He turned to Bill. "Have you?"

"Good Lord, no. I should never worry about a thing like that."

"I'm sure you wouldn't," laughed Antony. "Well, we can have a look when we go in. If the other keys are outside, then this one was probably outside too, and in that case well, it makes it more interesting."

Cayley said nothing. Bill chewed a piece of gra.s.s, and then said, "Does it make much difference?"

"It makes it more hard to understand what happened in there. Take your accidental theory and see where you get to. No instinctive turning of the key now, is there? He's got to open the door to get it, and opening the door means showing his head to anybody in the hall-his cousin, for instance, whom he left there two minutes ago. Is a man in Mark's state of mind, frightened to death lest he should be found with the body, going to do anything so foolhardy as that?"

"He needn't have been afraid of me," said Cayley.

"Then why didn't he call for you? He knew you were about. You could have advised him; Heaven knows he wanted advice. But the whole theory of Mark's escape is that he was afraid of you and of everybody else, and that he had no other idea but to get out of the room himself, and prevent you or the servants from coming into it. If the key had been on the inside, he would probably have locked the door. If it were on the outside, he almost certainly wouldn't."

"Yes, I expect you're right," said Bill thoughtfully. "Unless he took the key in with him, and locked the door at once."

"Exactly. But in that case you have to build up a new theory entirely."

"You mean that it makes it seem more deliberate?"

"Yes; that, certainly. But it also seems to make Mark out an absolute idiot. Just suppose for a moment that, for urgent reasons which neither of you know anything about, he had wished to get rid of his brother. Would he have done it like that? Just killed him and then run away? Why, that's practically suicide-suicide whilst of unsound mind. No. If you really wanted to remove an undesirable brother, you would do it a little bit more cleverly than that. You'd begin by treating him as a friend, so as to avoid suspicion, and when you did kill him at last, you would try to make it look like an accident, or suicide, or the work of some other man. Wouldn't you?"

"You mean you'd give yourself a bit of a run for your money?"

"Yes, that's what I mean. If you were going to do it deliberately, that is to say and lock yourself in before you began."

Cayley had been silent, apparently thinking over this new idea. With his eyes still on the ground, he said now: "I hold to my opinion that it was purely accidental, and that Mark lost his head and ran away."

"But what about the key?" asked Bill.

"We don't know yet that the keys were outside. I don't at all agree with Mr. Gillingham that the keys of the down-stairs rooms are always outside the doors. Sometimes they are, no doubt; but I think we shall probably find that these are inside."

"Oh, well, of course, if they are inside, then your original theory is probably the correct one. Having often seen them outside, I just wondered that's all. You asked me to be quite frank, you know, and tell you what I thought. But no doubt you're right, and we shall find them inside, as you say.

"Even if the key was outside," went on Cayley stubbornly, "I still think it might have been accidental. He might have taken it in with him, knowing that the interview would be an unpleasant one, and not wishing to be interrupted."

"But he had just told you to stand by in case he wanted you; so why should he lock you out? Besides, I should think that if a man were going to have an unpleasant interview with a threatening relation, the last thing he would do would be to barricade himself in with him. He would want to open all the doors and say, 'Get out of it'"

Cayley was silent, but his mouth looked obstinate. Antony gave a little apologetic laugh and stood up.

"Well, come on, Bill," he said; "we ought to be stepping." He held out a hand and pulled his friend up. Then, turning to Cayley, he went on, "You must forgive me if I have let my thoughts run on rather. Of course, I was considering the matter purely as an outsider; just as a problem, I mean, which didn't concern the happiness of any of my friends."

"That's all right, Mr. Gillingham," said Cayley, standing up too. "It is for you to make allowances for me. I'm sure you will. You say that you're going up to the inn now about your bag?"

"Yes." He looked up at the sun and then round the parkland stretching about the house. "Let me see; it's over in that direction, isn't it?" He pointed southwards. "Can we get to the village that way, or must we go by the road?"

"I'll show you, my boy," said Bill.

"Bill will show you. The park reaches almost as far as the village. Then I'll send the car round in about half an hour."

"Thanks very much."

Cayley nodded and turned to go into the house. Antony took hold of Bill's arm and walked off with him in the opposite direction.

CHAPTER VII. Portrait of a Gentleman

They walked in silence for a little, until they had left the house and gardens well behind them. In front of them and to the right the park dipped and then rose slowly, shutting out the rest of the world. A thick belt of trees on the left divided them from the main road.

"Ever been here before?" said Antony suddenly.

"Oh, rather. Dozens of times."

"I meant just here where we are now. Or do you stay indoors and play billiards all the time?"

"Oh Lord, no!"

"Well, tennis and things. So many people with beautiful parks never by any chance use them, and all the poor devils pa.s.sing by on the dusty road think how lucky the owners are to have them, and imagine them doing all sorts of jolly things inside." He pointed to the right. "Ever been over there?"

Bill laughed, as if a little ashamed.

"Well, not very much. I've often been along here, of course, because it's the short way to the village."

"Yes.... All right; now tell me something about Mark."

"What sort of things?"

"Well, never mind about his being your host, or about your being a perfect gentleman, or anything like that. Cut out the Manners for Men, and tell me what you think of Mark, and how you like staying with him, and how many rows your little house-party has had this week, and how you get on with Cayley, and all the rest of it."

Bill looked at him eagerly.

"I say, are you being the complete detective?"

"Well, I wanted a new profession," smiled the other.

"What fun! I mean," he corrected himself apologetically, "one oughtn't to say that, when there's a man dead in the house, and one's host-" He broke off a little uncertainly, and then rounded off his period by saying again, "By Jove, what a rum show it is. Good Lord!"

"Well?" said Antony. "Carry on, Mark"

"What do I think of him?"

"Yes."