“That Mark had killed Robert accidentally and had gone to Cayley for help, and that Cayley, having hidden him in the passage, locked the office door from the outside and hammered on it.”
“Yes, but you were so dashed mysterious about that. I asked you what the point of it was, and you wouldn’t say anything.” He thought for a little, and then went on, “I suppose you meant that Cayley deliberately betrayed Mark, and tried to make him look like a murderer?”
“I wanted to warn you that we should probably find Mark in the passage, alive or dead.”
“And now you don’t think so?”
“Now I think that his dead body is there.”
“Meaning that Cayley went down and killed him afterwards—after you had come, after the police had come?”
“Well, that’s what I shrink from, Bill. It’s so horribly cold-blooded. Cayley may be capable of it, but I hate to think of it.”
“But, dash it all, your other way is cold-blooded enough. According to you, he goes up to the office and deliberately shoots a man with whom he has no quarrel, whom he hasn’t seen for fifteen years!”
“Yes, but to save his own neck. That makes a difference. My theory is that he quarrelled violently with Mark over the girl, and killed him in sudden passion. Anything that happened after that would be self-defense. I don’t mean that I excuse it, but that I understand it. And I think that Mark’s dead body is in the passage now, and has been there since, say, half-past two yesterday afternoon. And tonight Cayley is going to hide it in the pond.”
Bill pulled at the moss on the ground beside him, threw away a handful or two, and said slowly, “You may be right, but it’s all guesswork, you know.”
Antony laughed.
“Good Lord, of course it is,” he said. “And tonight we shall know if it’s a good guess or a bad one.”
Bill brightened up suddenly.
“Tonight,” he said. “I say, tonight’s going to be rather fun. How do we work it?”
Antony was silent for a little.
“Of course,” he said at last, “we ought to inform the police, so that they can come here and watch the pond tonight.”
“Of course,” grinned Bill.
“But I think that perhaps it is a little early to put our theories before them.”
“I think perhaps it is,” said Bill solemnly.
Antony looked up at him with a sudden smile.
“Bill, you old bounder.”
“Well, dash it, it’s our show. I don’t see why we shouldn’t get our little bit of fun out of it.”
“Neither do I. All right, then, we’ll do without the police tonight.”
“We shall miss them,” said Bill sadly, “but ’tis better so.”
There were two problems in front of them: first, the problem of getting out of the house without being discovered by Cayley, and secondly, the problem of recovering whatever it was which Cayley dropped into the pond that night.
“Let’s look at it from Cayley’s point of view,” said Antony. “He may not know that we’re on his track, but he can’t help being suspicious of us. He’s bound to be suspicious of everybody in the house, and more particularly of us, because we’re presumably more intelligent than the others.”
He stopped for a moment to light his pipe, and Bill took the opportunity of looking more intelligent than Mrs. Stevens.
“Now, he has got something to hide tonight, and he’s going to take good care that we aren’t watching him. Well, what will he do?”
“See that we are asleep first, before he starts out.”
“Yes. Come and tuck us up, and see that we’re nice and comfortable.”
“Yes, that’s awkward,” said Bill. “But we could lock our doors, and then he wouldn’t know that we weren’t there.”
“Have you ever locked your door?”
“Never.”
“No. And you can bet that Cayley knows that. Anyway, he’d bang on it, and you wouldn’t answer, and then what would he think?”
Bill was silent; crushed.
“Then I don’t see how we’re going to do it,” he said, after deep thought. “He’ll obviously come to us just before he starts out, and that doesn’t give us time to get to the pond in front of him.”
“Let’s put ourselves in his place,” said Antony, puffing slowly at his pipe. “He’s got the body, or whatever it is, in the passage. He won’t come up the stairs, carrying it in his arms, and look in at our doors to see if we’re awake. He’ll have to make sure about us first, and then go down for the body afterwards. So that gives us a little time.”
“Y-yes,” said Bill doubtfully. “We might just do it, but it’ll be a bit of a rush.”
“But wait. When he’s gone down to the passage and got the body, what will he do next?”
“Come out again,” said Bill helpfully.
“Yes; but which end?”
Bill sat up with a start.
“By Jove, you mean that he will go out at the far end by the bowling-green?”
“Don’t you think so? Just imagine him walking across the lawn in full view of the house, at midnight, with a body in his arms. Think of the awful feeling he would have in the back of the neck, wondering if anybody, any restless sleeper, had chosen just that moment to wander to the window and look out into the night. There’s still plenty of moonlight, Bill. Is he going to walk across the park in the moonlight, with all those windows staring at him? Not if he can help it. But he can get out by the bowling green, and then come to the pond without ever being in sight of the house, at all.”
“You’re right. And that will just about give us time. Good. Now, what’s the next thing?”
“The next thing is to mark the exact place in the pond where he drops—whatever he drops.”
“So that we can fish it out again.”
“If we can see what it is, we shan’t want to. The police can have a go at it tomorrow. But if it’s something we can’t identify from a distance, then we must try and get it out.
