Outside, leaning on the gate where Deede Dawson had left him, Dunn was deep in thought that was not always very comforting, for there was very much in all this laid out for him to accomplish that he did not understand and that disturbed him a good deal.

A careful, cautious "Hist!" broke in upon his thoughts, and in an instant he stiffened to close attention, every nerve on the alert.

The sound was repeated, a faint and wary footstep sounded, and in the darkness a form appeared and stole slowly nearer.

Dunn poised for a moment, ready for attack or retreat, and then all at once his tense att.i.tude relaxed.

"You, Walter," he exclaimed. "That's good! But how did you get here? And how did you know where I was?"

The new-comer drew a little nearer and showed the tall, thin form of Walter Dunsmore to whom Dunn had spoken at Wreste Abbey.

"I had to come," he murmured. "I couldn't rest without seeing you. You upset me the other day, saying what you did. Isn't it very dangerous your being here? Suppose Deede Dawson--"

"Oh, if he suspected, there would soon be an end of me," answered Dunn grimly. "But I think I'm going to win--at least, I did till tonight."

"What's happened?" the other asked sharply and anxiously.

"He has been telling me his plans," answered Dunn. "He has told me everything--he has put himself entirely in my power--he has done what I have been waiting and hoping for ever since I came here. He has given me his full confidence at last, and I never felt more uneasy or less certain of success than I do at this moment."

"He has told you--everything?" Walter Dunsmore asked. "Everything, except who is behind it all," answered Dunn. "I asked him who he was acting for, and he refused to say. But we shall know that tomorrow, for he told me something almost as good--he told me where this employer would be at four o'clock tomorrow afternoon. So then we shall have him, unless Deede Dawson was lying."

"Of course, it all depends on finding that out," remarked Walter thoughtfully. "Finding out his ident.i.ty."

"Yes, that's the key move to the problem," Dunn said. "And tomorrow we shall know it, if Deede Dawson was speaking the truth just now."

"I should think he was," said Walter slowly. "I should think it is certain he was. You may depend on that, I think."

"I think so, too," agreed Dunn. "But how did you find out where I was?"

"You know that day you came to Wreste Abbey? There was some fellow you had with you who told the landlord of the Chobham Arms, so I easily found out from him," answered Walter.

"Anyhow, I'm glad you're here," Dunn said. "I was wondering how to get in touch with you. Well, this is Deede Dawson's plan in brief. Tomorrow, at four in the afternoon, Rupert Dunsmore is to be killed--and I've undertaken to do the deed."

"What do you mean?" exclaimed Walter, starting.

"I've promised that if Deede Dawson will bring me face to face with Rupert Dunsmore, I'll murder him," answered Dunn, laughing softly.

"A fairly safe offer on your part, isn't it?" observed Walter. "At least, unless there's any saving clause about mirrors."

"Oh, none," answered Dunn. "I told Deede Dawson Rupert Dunsmore was my worst enemy, and that's true enough, for I think every man's worst enemy is himself."

"I wish I had none worse," muttered Walter.

"I think you haven't, old chap," Dunn said smilingly. "But come across the road. It'll be safer on the common. Deede Dawson is so cunning one is never safe from him. One can never be sure he isn't creeping up behind."

"Well, I daresay it's wise to take every precaution," observed Walter.

"But I can't imagine either him or any one else getting near you without your knowledge."

Robert Dunn,--or rather, Rupert Dunsmore, as was his name by right of birth--laughed again to himself, very softly in the darkness.

"Perhaps not," he said. "But I take no chances I can avoid with Deede Dawson. Come along."

They crossed the road together and sat down on the common at an open spot, where none could well approach them unheard or unseen. Dunn laid his hand affectionately on Walter's shoulder as they settled themselves.

"Old chap," he said. "It was good of you to come here. You've run some risk. It's none too safe near Bittermeads. But I'm glad to see you, Walter. It's a tremendous relief after all this strain of doubt and watching and suspicion to be with some one I know--some one I can trust--some one like you, Walter."

In the darkness, Walter put out his hand and took Dunn's and held it for a moment.

"I have been anxious about you," he said. Dunn returned the pressure warmly.

"I know," he said. "Jove, old chap, it's good to see you again. You don't know what it's like after all this long time, feeling that every step was a step in the dark, to be at last with a real friend again."

"I think I can guess," Walter said softly.

Dunn shook his head.

"No one could," he said. "I tell you I've doubted, distrusted, suspected till I wasn't sure of my own shadow. Well, that's all over now. Tomorrow we can act."

"Tell me what I'm to do," Walter Dunsmore said.

"There's a whole lot I don't understand yet," Dunn continued slowly.

"I suppose it was that that was making me feel so jolly down before you came. I don't feel sure somehow--not sure. Deede Dawson is such a cunning brute. He seems to have laid his whole hand bare, and yet there may be cards up his sleeve still. Besides, his plan he told me about seems so bald. And I don't understand why he should think he is so sure of what I--I mean, of what Rupert--it's a bit confusing to have a double ident.i.ty--is going to do. He says he is sure Rupert Dunsmore is to be at the Brook Bourne Spring tomorrow at four. He says his information is certain, and that he has full knowledge of what Rupert Dunsmore is going to do, which is more than I have. But what can it be that's making him so sure?"

"That's probably simple enough," said Walter. "You said you suspected there was a leakage from Burns & Swift's office, and you told Burns to make misleading statements about your movements occasionally when he was dictating his letters. Well, I expect this is one."

"That may be; only Deede Dawson seems so very sure," answered Dunn. "But what's specially important is his saying that his employer, whoever it is, who is behind all this, will be there too."

"A meeting? Is that it?" exclaimed Walter.

"No, that's not the idea," answered Dunn. "You see, the idea is that Rupert Dunsmore will be there at four, and that I'm to be there in ambush to murder myself. Whoever is behind all this will be there too--to see I carry out my work properly. And that gives us our chance."

"Oh, that's good," exclaimed Walter. "We shall have him for certain."

"That's what I want you to see to," said Dunn. "I want you to have men you can trust well hidden all round, ready to collar him. And I want you to have all the roads leading to Ottam's Wood well watched and every one going along them noted. You understand?"

"That's quite easy," declared Walter. "I can promise not a soul will get into Ottam's Wood without being seen, and I'll make very sure indeed of getting hold of any one hiding anywhere near Brook Bourne Spring. And once we've done that--once we know who it is--"

"Yes," agreed Dunn. "We shall be all right then. That is the one thing necessary to know--the key move to the problem--the ident.i.ty of who it is pulling the strings. He must be a clever beggar; anyhow, I mean to see him hang for it yet."

"I daresay he's clever," agreed Walter. "He is playing for big stakes.

Anyhow, we'll have him tomorrow all right; that seems certain--at last."

"At last," agreed Dunn, with a long-drawn sigh. "Ugh! it's all been such a nightmare. It's been pretty awful, knowing there was some one--not able to guess who. Ever since you discovered that first attempt, ever since we became certain there was a plot going on to clear out every one in succession to the Chobham estates--and that was jolly plain, though the fools of police did babble about no evidence, as if pistol bullets come from nowhere and poisoned cups of tea--"

"Ah, I was to blame there, that was my fault," said Walter. "You see, we had no proof about the shooting, and when I had spilt that tea, no proof of poison either. I shall always regret that."

"A bit of bad luck," Dunn agreed. "But accidents will happen. Anyhow, it was clear enough some one was trying to make a jolly clear sweep. It may be a madman; it may be some one with a grudge against us; it may be, as poor Charley thought, some one in the line of succession, who is just clearing the way to inherit the t.i.tle and estates himself. I wish I knew what made Charley suspicious of Deede Dawson in the first place."

"You don't know that?" Walter asked.