It was after midnight when Steve finally decided that it was safe to venture from their retreat. And then they did not emerge by the way in which they had entered it.

"This place has saved the life of many a Servian patriot in these last few years," said Steve. "I think the Austrians have come near to finding it once or twice. They have pursued some of our people to the very entrance. But what has always puzzled them is that we never go out by the way in which we come in. And one entrance we have never used except for flight, and then only in a grave emergency. No Austrian pursuer has ever seen that, or come near it. It is the one by which we shall escape now. Keep still. That is all that is necessary. Keep still and follow me."

Dick had guessed already that there were other entrances. He was not prepared, however, for the elaborate system of rooms and passages that were revealed as he followed Steve, who had now possessed himself of an electric flashlight, and had given Dick one also.

"We could almost have stood a siege down here," explained Steve. "Here—we seem to be in a dead alley, don't we?"

They had passed from the room in which they had waited to another, where Dick had seen a plentiful supply of provisions and of drinking water in great bottles. From this they had gone into a narrow passage, dark and damp. Now Steve flashed his light on a blank wall. But a touch at the right place brought a handle into view. This, when it was pulled, showed that there was really a door, cunningly made so that it seemed to be a part of the wall, with no cracks to betray it. And behind this was another door of solid steel.

"It would not be easy to get through that door, you see, even if they penetrated the secret of the first one," said Steve. "That door is made of armor plate, of tempered steel. It is the same sort of steel that is used for the protection of a great battleship. Even a shell from a cannon would not go through it very easily, and bullets would only be hurled back if they struck it."

He touched a spring and the door revolved on its own axis, staying open just long enough for them to pass through, and then closing.

"The action is automatic," said Steve. "That would make it safe even if one were pursued, for the pursuer would be caught as the door closed; he would not be so close as to be able to get through."

"You people didn't overlook anything, it seems to me," said Dick. "You must have been getting ready for war for a long time."

"For years," said Steve, quietly. "Ever since King Peter came to the throne and refused any longer to betray the country to Austria, as his predecessor did always. We stand in Austria's way. Until we became powerful by beating Turkey and Bulgaria, which attacked us as the result of an Austrian trick, it mattered less. But ever since the end of the second war last year we have known that Austria was only looking for an excuse to attack us. And so we have tried to be ready. It was our only chance."

"But you say you won't have to fight Austria alone. The Russians will come to Servia's aid, won't they?"

"In a way, yes. But they will not be able to send troops to fight with our armies. They may attack Austria, and so keep some of her soldiers busy elsewhere. But that is all. We do not touch Austria anywhere. She might send troops through Roumania, and Roumania, it is true, is friendly toward us. But that would bring her into the war, and she will not be ready for that for a time. At least Turkey would bar her from sending troops by sea to Antivari, for they would have to pass through the Dardanelles, and that is impossible since Turkey is the friend of Germany.

"And there is another point. Austria has been making ready. She can strike quickly. Russia is slow. It will be two months before she makes herself felt, even if she declares war at once. For two months Austria can devote herself almost entirely to us. And the odds in her favor are so great that anything might happen in that time, if we had not prepared for her. As it is, there is almost nothing of Austria's plans and preparations that we do not know."

While Steve talked they were walking through what seemed almost like a tunnel. Now he flashed his light, looked about, and dropped his voice.

"Now we must begin to be careful," he said. "We are getting near the light. This is like a rabbit's warren, but soon we shall be in the open. Sure as we are that the Austrians know nothing of this place, we never take chances."

"We must be a long way from the cellar we first went into," said Dick. "Even if we've circled around, and here where there are no stars, I can't tell about that. We've walked a long distance, I should say."

"You're right," said Steve, with a low and discreet chuckle. "Oh, this is a fine tunnel! Do you know what we did a few minutes ago? We walked right under a police station!"

The tunnel seemed to dip now, and then to rise again. And in a few moments cold air was blowing on their faces; cold, that is, by comparison with the heat of the subterranean workings in which they had been buried. Then they came out, stooping, and passing through a well designed covering of shrubs and bushes, on the sandy beach of the river. Dick gasped a little at that, and at seeing that they had evidently got out of the town altogether. Before him now lay the lights of Belgrade, but he noticed one thing at once. The lights had shrunk; there were fewer than there had been the night before.

Steve had gone ahead now, scouting to see if the coast were clear, but he returned in a moment, jubilant.

"All safe!" he said. "I knew it would be, of course, but there is no need to take chances. Now we're all right so far. But we've got quite a walk before us yet. We'll still be very cautious."

"Which way?" asked Dick.

"West, along the bank of the Save here. Look, do you see that monitor there? If her searchlight swings this way, drop down. She might not pay any attention, but we don't want to be noticed at all, and it's better to be on the safe side."

"Why are there so few lights in Belgrade?" asked Dick. "I know it's late, but other nights, when I've looked over, it was much brighter."

"I'm not sure," said Steve, looking anxious. "You see, it's hours since I've had any news. The war may have come already, Dick. I hope not, because I should feel that we were more sure of getting across before the declaration. Still we have a good chance, even if it has begun."

Three times, as they walked along the river bank, Steve made a long detour inland.

"The Austrians have patrols along the river," he said. "But they don't take that sort of work very seriously. They are trusting the monitors and their searchlights. You see, their lights are swinging pretty steadily, and they cover the whole river and the Servian shore."

"And don't they think that there's likely to be danger on this side?"

"They're right, too, of course. Spies, yes. But we couldn't threaten them very seriously in any way that would make it necessary for them to be very careful here."

"I wish we knew what was going on, don't you? Doesn't it seem funny to be right in the middle of something that's going to make history and to think that people thousands of miles away really know more about it than we do?"

"Yes. But soon we'll know all there is to be known. When we're once over the river, then we can ask questions and get true answers, which is more than people in Semlin have been doing lately. Yes, I'm just as anxious for some news as you are. I rather wish now that I'd gone out while we were waiting for it to be late enough to start. But I suppose it was better that I didn't. You'd have been helpless there if anything had happened to keep me from coming back," remarked Stepan.

"If you'd been caught, you mean?"

"Ye—es, I suppose that's what I mean. Although really I don't think there was ever any great danger of that. When I got a job from Hallo, it was sure that no one suspected me, because he's so busy with government contracts that he had to be careful. I'm supposed to be a Hungarian, from Buda-Pesth. And it isn't as if I'd been trying to find out things in a general way. All I had to do was to pick up the information that it was so easy to get in Hallo's place. There were all sorts of things to be learned there, and a lot was made easy for me because Hallo and others didn't think, I suppose, that I would know what certain papers and estimates meant."

"How did you know enough to be able to do all that sort of thing, Steve?"

"Well, there were a lot of things I didn't understand, myself. But I didn't have to. I just copied down everything I saw that seemed to have anything to do with military matters in any way, and sent everything I got to the general staff at home. They knew the meaning of everything, you see. It wasn't any one thing, perhaps; it was what I and a lot of others who were at work over here were able to report that counted. They could put one thing with another, and, altogether, it was worth something. I don't know how much. But I do know, for instance, that Hallo has sent supplies of various sorts to particular places. There's a regular arsenal on the Austrian side, near Schabatz, and there are big depots of supplies at a lot of places along the Drina."

"Oh, I understand better now. Hallo is supplying food and things that the soldiers will need?"

"Food, and shoes, mostly. He's the biggest contractor for those, but he is handling about everything. Medical supplies, uniforms, horseshoes, saddles, and a tremendous lot of petrol—gasoline. And he's making a big profit, too. He's one of several big army contractors who have been eager for this war, and have had a lot to do with bringing it on, because they hoped to grow richer out of their contracts. War meant big profits."

"Men like that ought to have to do some of the fighting themselves, I think! But they never do. They stay behind, and let others do the work. I've heard about that sort of thing at home in America. And some of them didn't even behave honestly. They sold bad beef for the soldiers, and rotten leather, and shoddy cloth for uniforms."

Steve chuckled.

"I'll tell you something about Hallo," he said. "But remember not to tell anyone else, even if you get a chance, until the time comes. He's doing something like that, too. He thinks he's been very clever, and that there's no chance for anyone to find him out. But I've got the proof, and perhaps there'll be a chance for you to use what I know to make him do what's right for your mother, Dick. As it is, you see, I wouldn't give him away, because it's good for us to have the Austrians badly equipped. Hello, we're getting near our ferry! Do you see that blasted tree there—the one that was struck by lightning?"

"Yes," said Dick, peering through the darkness.

"Well, just below that there ought to be a boat and a man with it. We'll soon know if we can row or if we'll have to swim for it. It's a long swim, and I'm not anxious to go that way."

But the boat was there, and beside it a Servian who greeted Steve happily, and looked at Dick appraisingly.

"He is with me," said Steve. "Jump in, Dick! Hurry, Mischa!"

In a moment they were out in the stream. And then things began to happen. There was a sputtering of fire from the bank they had left, and Mischa, the ferryman, staggered and collapsed. A bullet had reached him! The oars fell into the water, and they were adrift.