"You, Dick? Thank God!" cried Stepan. Then his face flushed, and he came forward, furiously. He dragged the spy out, looked at his face, and then spurned him with his foot.

"You saved my life, I think, Dick," he said, simply. "I never suspected this! Treachery in our ranks. I had not supposed that any Servian would sell his country. Mike Hallo, of course, we never trusted—but this man! Well, he will pay in one way or another."

"I knew what was going to happen. I was here and heard them talking."

"I didn't even know he had come. I had made some discoveries below, and was hard at work. I knew that Hallo would not leave without my knowledge. He would not have wanted to leave me here alone in the warehouse. But, Dick, how did you get here? How did you come to leave the boathouse? I asked you to wait there, you know."

"How did you know I had gone?"

"Vanya, the soldier, told us. I sent him to fetch you. And when we learned that you had gone, we suspected that Hallo had had some part in it, for by then I had been told that he had escaped after they had caught him. But you don't know about that—"

"Don't I though? I was there listening, while he told this other fellow all about it. He was in the boathouse when we landed, Steve!"

"Ah! I knew it! I told Milikoff so! That was how he escaped! But how did you come here—free?"

Dick told his story as quickly as he could; told of how he had escaped from detection in the boathouse because Hallo had been even more frightened than he himself, if anything, and of his wild chase after the Hungarian.

"I was afraid I had done wrong in going—afraid that I should have stayed in the boathouse and waited for you to come. Did you come here after me, Steve? Wasn't that your purpose?"

"Yes, in a way. I thought that Hallo had something to do with your disappearance, and I never dreamed of your being able to fool him as you did! But I should have come in any case. Milikoff and I had decided that before we knew that you had vanished. And if you hadn't been here, Dick, they would have killed me, I think, when this wretched traitor told Hallo that I had been deceiving him."

"He told him more than that, though Hallo did not know it was you of whom they talked, Steve. This spy told him that you were the most dangerous of all—and Hallo said he didn't believe there was any such person as Stepan Dushan!"

They both laughed, and Steve laughed still more when he heard of Hallo's mystification and fury about the revelation of the hiding places of the stores on the Drina.

"That was what made us sure that Austria had decided for war," he said. "We knew that she would not prepare for an invasion there so secretly otherwise. That was why we knew that it would be useless to agree to her terms, even if that had been possible."

"Hallo said no one but himself knew about those stores."

"He was nearly right—but a miss is as good as a mile," said Stepan, with a laugh. "He knew—and the staff knew—and I knew! I found out all about those things by reading his private letters, Dick. That was the part I hated most about the work. I had to read all his letters after we became sure of what he was doing. It made me feel wretched at first, as if I were doing something very dishonorable."

"But you weren't doing it for a dishonorable reason, Steve. Still I can see how you felt."

"But I didn't feel that way very long, Dick, because I soon found out what a miserable cheat and swindler he was! You were surprised, you know, when you found out that I knew all about you."

"I certainly was! I never was so much surprised in all my life!" said Dick very quickly.

"Well, I may have some more surprises for you still, Dick. I'm not sure, but I do know some things I haven't told you yet."

"You do, Steve? Why can't you tell me now?"

"I can, but I want to make sure that they will be of some use to you before I do. If I told you some things I know, they might make you change your plans, and then they might not be of any value, after all. They might only put you off. You see, when I first found out these things about the way he had treated you, I didn't know you and didn't have any reason at all to suppose that I ever would, or that I'd ever even see you. New York's a long way off—and, of course, I was more interested in what was going on here, because I knew that this war might come along at any moment, and I was here just to see what I could do for Servia and to interfere with the things we had reason to suppose Mike Hallo was doing for the Austrians."

"Of course. I can understand that, Steve. There wasn't any reason for you to do as much as you did, and to take all the interest you did in me, when you didn't know anything about me."

"Well, at first I just wanted to help you because I hated him so. I thought there was a chance to spoil the trick he was trying to play on you. When I found that he was planning to get rid of you by having you arrested before you could get back to the American consulate I wanted to trip him up."

"You certainly did a lot for me, Steve. I don't know whether I'll ever be able to get anything out of him, but if I do it will be due to you. If they had ever got me out of here and away to Buda-Pesth, I'd never have been able to come back, even if they had not managed to trump up some charge against me and kept me in prison for a long time."

"Oh, they would have done that, Dick, of course. That was the idea. And it's very easy for them to manage such things here. As easy as it used to be in France before the revolution there."

"What are we going to do now, Steve?"

Dick looked down at the helpless figures of the two men on the floor. Neither of the scouts had paid much attention to them as yet, but now they leaned down and examined them.

"They're not badly hurt," said Steve, contemptuously. "They saw the crate falling and so did I. And they tried to jump. So it didn't fall full on top of them, but struck glancing blows on their heads and almost pushed them out of the way. I don't see how you ever got it going at all, all by yourself! It looks terribly heavy."

"I think it was because it wasn't very well balanced, Steve. If it had been turned the other way probably I couldn't have budged it. But the heavy end was on top, which made it go over. I sort of jumped at it, and that gave it the start."

"I'm afraid we'll have to leave them here," said Steve. "I wish there was some way for us to take them along, but I don't see how we can. We might be able to drag Hallo with us, but we wouldn't get very far."

"I suppose not. He has lots of friends, hasn't he? I saw ever so many people stop and speak to him when I was following him on the way here."

"I don't think he's got many friends, but there are a lot of people who know him, all right. Still, it isn't that—it would be making ourselves conspicuous by having him with us at all."

"It would be a good thing to take him, though, if we could, wouldn't it?"

"Oh, yes. The best thing in the world! If we could only get him to our boat and carry him back to Belgrade!"

"Steve, how about the men who are working in the tunnel under the arsenal?"

"What do you mean? What do you know about the tunnel under the arsenal?"

Steve was startled and dismayed, but Dick laughed at him.

"That's all I know," he said. "Just that there is such a thing, Steve. You needn't be frightened—I haven't been spying around. But this man that came here to see Mike Hallo knew all about it. He told him the mine was going to be sprung to-night, and that they must hasten to stop it."

"That ends the last doubt! He is a traitor!" said Steve. "He surely will have to pay the price of treachery, too, when there is an opportunity."

"Do you mean that they will kill him?"

"What else can be done? It is his life against a nation, Dick. A man like that may cause a thousand deaths by betraying a single secret. But—about the men in the tunnel. I might have known that there was some good reason for your knowing. Yes, it is true. There are men working there, and they will try to explode their mine and blow up the arsenal to-night."

"Can't you reach them? I think that two or three men might get Hallo through the town and to the boathouse. They could pretend that he was drunk, and that they were helping him along, if he was still unconscious."

"Dick, I think you've hit on the right idea again! I'll try to get them. But suppose they come to first?"

"If we tied them up?" was Dick's suggestion.

"It would be risky. The watchman may come here at any moment after he hears no more voices."

"Yes, that's so. How long would it take you to go?"

"To go and come back? Twenty minutes, perhaps."

"Then go! Don't delay any longer, and I will stay here and keep watch."

"In here? No, it is too dangerous. I am afraid now, if they learn what you have done for us, they will be able to make a real charge against you, and that even your consul could not help you to escape severe punishment."

"I would not wait here—not in here, Steve. I would watch outside. Look! Do you see these grains of corn?"

He picked up a handful of the kernels from a sample basket on the table.

"Yes. What about them, Dick?"

"I will keep watch. If he comes out, I will follow him and every three or four feet I will let a little of this corn drop, so that it will mark a trail for you to follow. Do you see the idea?"

"Yes, and that is magnificent, Dick! That is the best chance we shall ever have of catching him. It will be better for him to come out, for he will lead you away from the busier part of the city, perhaps, so that it will be easier for us to take him! I'm off! I think we have a chance to get the scoundrel this time, thanks to you!"

They slipped out together, leaving the two unconscious men.

"I think Hallo will come to before long," said Dick. "The other will take longer for he seemed to be more badly stunned, or else he's not as strong as Hallo. Will Mike leave him there, do you think?"

"Yes. Why not? He will be thinking of his own precious skin, you may be sure. Good luck, Dick! I'll be back just as soon as I can!"

"Yes—hurry! But I think we'll be all right."

Dick took his place in a dark doorway on the opposite side of the street and began his vigil. The seconds seemed to drag by endlessly, but Dick never took his eyes from the entrance of the warehouse. And at last—he had really been waiting less than ten minutes!—he was rewarded. Hallo came out holding his hand to his head, staggering a little as he walked. Dick gave him a start, and then crossed and followed. He dropped his corn as he went, and his hand was on the automatic pistol in his pocket, which somehow gave him a sense of security.

Hallo turned a corner; Dick hurried a little. And, as he rounded the corner in his turn, there was Hallo—waiting! At the sight of Dick he almost screamed, but choked the cry.

"So it's you, is it?" he cried. He made a savage rush, his arms outstretched like those of a gorilla.