 America's number one adventurer, K-7, from a United States secret agent who operated in 22 countries, on land, on sea, and in the air, brings you another story of today. Here is K-7. Ladies and gentlemen, undoubtedly you have read much about fortified borders during the past year. Pictures of these modern spite fences between nations have appeared in publications. Not only one, but many nations now possess them, or they are building them. Are they new? Many seem to believe they are. Yet they are as old as the Great Wall of China. John Holbrooke will introduce the story of a modern plot involving the mining of such a barrier. Thank you, K-7. Fortified borders have always had one great weakness. They can be mined and blown up. K-7 and his friend Agent Z were in active service when Kimmel Hill was blown up during the World War. That experience led Agent Z to work swiftly when the case now to be dramatized came to his attention. Our story opens as two men study a map. Here's the map of the border. The red line shows where the fortifications will be put in. You are sure this map is accurate? It is an exact copy of the approved plans. The plans will photograph for us in the Department of Military Information. This plan was drawn from the photographs. Yeah, but what is your plan? It is simple, my friend. Work on the border has already been started to the north. Now, look at this spot. Yes. It has been surveyed by military engineers, but work will not begin for at least three months. You see this hill? Yes, of course. It is a vital point. The fortifications are to be heaviest here. The entire hill is to be hollowed out. When the work is completed, that hill will contain the air conditioning equipment and munition sellers, officers' quarters and telephone headquarters. It will be the nerve center. That is very interesting. We are going to mine that hill before actual construction on the border starts. Then we will sell our work. Think what it will mean. When we are finished, a button can be pushed in the city hundreds of miles away, and the nerve center of the border will be blown to bits. Yes. It will be worth at least $5 million to us. Perhaps more. Now, follow me closely. Do you see this farmhouse sketched on the map? Yes, yes. It is deserted and at the foot of the hill. We begin work there. The river is within a few feet of the door. The dirt, which we dig out of our tunnel, can be disposed of in the river. This is a perfect plan, Shostak. This will be George Shostak's masterpiece, Petron. When we are finished, the hill is mined. I will retire. When shall we start? Tomorrow night. The plan was perfect. The border was to be mined before the fortifications were built. However, there was a slip. The traitor, in the office of military information, who had made the photographs of the plans, was found using his camera again. He was secretly seized in question. The information which he gave brought Agent Z into the case. Z and his assistant, Patricia Norwood, began their investigation at once. What an afternoon you picked to come out here, Z. Well, I picked it deliberately, Pat. We don't want to be seen. If it storms, so much the better. Let me try and help you with that heavy cage. Oh, it's all right. I can handle it. We're almost at the top of the hill. This is the spot. Are you going to set the sound detector up now? No, not until night. I'll conceal it in these bushes. There, there, that hides it. Now we'll have a look around. It's peaceful enough, Z. I can't believe that within a few short months, this hill will be bristling with guns. Yes, it'll have more than guns, Pat. This hill will be the nerve center of the entire border. Across that river below us lies another country. There'll be fortifications there, too. It's horrible to think of. Yes, and even worse, to think that tonight, there may be men burrowing beneath where we're standing. Burrowing to plant mines that will explode and kill other men whom they've never even seen. But come on, Pat. We've got work to do. You're sure this is the place? There's no doubt about that. The trader who sold the plans to George Shostack broke down completely. He told everything he knew. Our job is to find out first if Shostack has started work. Then we've got to capture him and take the copy of the plans from him. Z, look at the river. It's muddy from the rain this morning. But it's yellow mud. And the soil along the banks is black. Oh, what's that? Pat, you're right. I didn't notice. Black soil, yet the water is yellow. And it doesn't extend above this point. Look at the river. What does it mean? It may mean that you've discovered something, Pat. We've got three hours before night. First, I'm going to have a look around. Then we're going to take samples of that river water and analyze it. A few hours later, Z is in his laboratory. He looks up from a powerful microscope he's using. Pat, you made a vital discovery when you noticed the yellow color of the river. That yellow color was caused by dirt dug from far underground. You're sure? I'm positive. It's the yellow clay. One of the peasants told me they always struck yellow clay when they dug a deep well. Then it means that someone is digging. Unless I'm mistaken, it means that George Shostack is at work. Now we'll get started back to the hill. If our sound detector confirms what this yellow clay seems to prove, there we'll find out within a few hours. Get ready, Pat. We're going back. Under cover of darkness, Pat and Z again made their way to the top of the hill. There, Z set up a sound detector, a delicate instrument that picks up sound that cannot be heard by human ears. Can you see what you're doing, Z? It's so black tonight. That's a perfect night for us, Pat. We can't afford to use a flashlight. It might be seen. I'll have this working in a minute. Will we be able to hear them at work under it? We will if they're down there. This machine is like a delicate pair of ears, Pat. It'll pick up the slightest sound. Oh, something like those machines with huge horns? They use an anti-aircraft work? The ones that pick up the sound of airplanes approaching at night? Yeah, something like them, Pat. There is a small speaker here in this cabinet. The machine is tuned to something like a radio. If there are men digging a tunnel under us, we will hear the sound of their picks and shovels. And I'll see, now almost ready to snap this switch on first. It's working. Now let's see what we can find by tuning. What does that mean? Nothing yet. There's something. Now if I can tune it in. The? The, they're down there. There's no doubt about it, Pat. George Shostack has started his tunnel. Have you epistle with him? Yes. Good. Now I want you to stay here. I'm going down to the river bank and travel along it until I find where that clay of the colors of water is being carried out. But the, it's so black tonight. If anything should happen to you, I wouldn't know where to find you. No, nothing will happen. I want you to stay right here by the sound detector. And if I need you, I'll fire two shots. If you hear shots, come at once. I will. Be careful. Don't you worry about me, Pat. Just stay there unless you hear two shots. Ze reached the bank of the river and made his way slowly downstream in the blackness. His eyes grew used to the night. And to his left, he saw the outlines of the deserted farmhouse. Farmhouse? No lights. Deserted. Just the kind of a place Shostack would pick. It doesn't seem to be anybody around. I think I'll have a look inside. There's a porch. Who's there? Answer me. Answer me or I'll shoot. Stop. Stop. Do you hear me? Stop. What happened? I heard shots. They were mine. I heard something. It was on the porch. I shot twice. Was it a man? I don't know. I called, no one answered. And I shot. Something ran into the bushes. An animal, probably. You fool. You want us to be heard? I would stay with you for a minute. We're just calling you two at the terminal. But I'm sure I heard something. I can't see tonight. Zee? Zee, where are you? There's someone. Listen. Zee? Far again. She's a good girl. She's coming back. Zee? Zee, are you here? Zee, sir! Honey doll, who are you? I was about to ask you that same question myself. What are you doing here? I was looking for someone. Obviously. But for whom? For my brother. He's just a boy. He was out hunting this afternoon. He didn't come home. I heard the shot. You lie, ma'am, sir. It's the truth. I've been looking for him ever since it got dark. I heard the shots and thought he was signaling. Let's take her inside and see what she looks like. Shut up. So you know my name, ma'am, sir. Yes, Peyton. I think we have better look at her. She's probably a spy. Open the door. Yes. Wait. There was a signal. Stand still. It cannot be seen. Ma'am, sir, if you attempt to move. We should get away. There will be time for that. Keep the girl between us. If you try to run, ma'am, sir. Shostek, I won't try to run. I have a gun in your bag. If you move or that man Peyton moves, I'll shoot. You should have searched me, Shostek. Oh, my pleasure. It's on us. And you're both covered. This place is surrounded there. You all right, Pat? Yes, V. I'm holding a gun in Shostek's bag. Yeah, wait a minute. I'll handcuff them together. Who are you? It's the police. Your man is partially right, Shostek. I'm Special Agent Z. You're both under arrest. Z. There are others below us working in a tunnel. Shostek mentioned them. Is this place really surrounded? Not yet, but it will be in another 10 minutes. But the signal, the whistle. I blew that, Pat, to make them think there were more of us. When this man Peyton fired at me, I knew you'd hear the shots and come. We arranged two shots as a signal. I got away in telephone for help. I wondered. We'll stay here quietly until that helper arrives. Shostek, perhaps I can amuse you by telling you some stories about your old friend K7. If you know K7 very well, I'll send him a cable tomorrow morning. A cable saying, George Shostek is again in prison. This time, he'll be tried as a spy. George Shostek has been a spy and international crook since the days before the world war. And now I leave you with this thought. Contrast our position in North America with that of the other nations. They erect fortified borders between themselves and their neighbors. Canada and the United States have a border thousands of miles long and there is no fort or fortification. Our countries are friendly neighbors who live in peace with each other as all nations could if they so will. Listen for my next story. This is K7 speaking.