 In the excitement and confusion of a fight staged by Tarzan, Dhanu and Dukar, the Rattorian, climb unobserved to the roof of a watchtower on the edge of the wall surrounding the city of Tor. Later in an attempt to scale the wall under cover of darkness, the two men are recaptured by the Torians and sentenced by Artea to the fires of Tor. Tarzan, Oruk, Jeanette and Ashley are confined in a dungeon to await death by sacrifice. Wong Tai escapes the sentence through his suave flattery of the Torian Queen. High in the wall of their dungeon, Tarzan discovers the entrance of a narrow tunnel through which he leads his companions to a large cavern from which several lighted corridors branch off. At the sound of approaching voices, the little group hastens into one of the corridors. Rounding a sharp turn, they're abruptly confronted by a huge snarling black leopard chained to the wall directly in their path. They find them, the voices of the approaching yellow men grow louder. Why, Joe, Tarzan, we're in for it. We can't go back. Those yellow devils are coming along this passage. And we can't go ahead. That savage group would tear us to rags. Oh, what are they gonna do? Isn't there some way we can get by him? The chain's too long, Okhushla. It rages clear across the corridor. What's the devil's idea of tying a leopard in an open passageway like this anyway? My Joe, I believe, is chained beside the entrance to a branch passage. Look there, Tarzan. Isn't that a... Right. And that's where we're going. Whatever we decide on doing, we've got to do it quickly. Those fellas are getting closer. They'll never look for us in a tunnel guarded by Sheetah. Oh, but we can't even pass him, let alone get into that corridor. Mind that. You stay here. Watch the passage beyond from this bend. I'll take care of Sheetah. When I call a roark, get into that corridor fast. Eyes alertly watching, Sheetah. Tarzan walks steadily toward the great black jungle terror whom even new mother lion hesitates to attack. Darling, savage day, Sheetah sinks slowly to the ground, gathering himself for the charge. The cruel yellow eyes blaze evilly as the eight man moves cautiously forward. Suddenly, with a blood-chilling scream of savage rage, Sheetah bounds forward. Quickest thought, Tarzan pulls himself aside. While Sheetah's screaming angrily flashes past his shoulder, he grasps the chain, jerks the black killer to a standstill on his hind legs. Like an arrow shot from a bow, the eight man leaps in. His mighty arms encircle the brute's neck in a death-dealing stranglehold. At the bend in the corridor, a roark, Jeanette and Asley watch in fascinated silence, the approaching yellow men momentarily forgotten. Lifting the black terror clear of the ground, Tarzan shouts, Now, into the tunnel, quick. Come on, Jeanette, carry. He's got him. The three disappear into the mouth of a cross passage. Tarzan dragging the snarling fighting brute with him backs into the entrance of the tunnel just as several yellow men appear around the bend in the main corridor. The eight men's steel-muscled arms tighten about the black throat in one mighty effort. Sheetah admits a last-choked snarl. Tarzan drops the half-strangled brute to the ground. In two strides, he's overtaken his companions. Come on. Those men won't come to the mouth of this tunnel because of Sheetah. But to be on the safe side, we'll get out of sight. If they find the dead cat, they'll know that we're around. Sheetah is not dead. Only choked a little. You didn't kill the brute? For the very reason no roar cares in mind. If they had bound Sheetah dead, they would have known of our presence in this tunnel. Be good, he know what. The tunnel is going up. And a pretty steep ascent, too. Any idea where we are, Tarzan? Somewhere under the central tower. That's as near as I can guess. Why do you suppose that leopard is chained out there in front of that corridor? To keep anyone from entering this passage. But surely, but why just this passage more than any other? There must be something at the end or in this tunnel that our tail wants protected. We'll probably find out before long. There are several things I'd like to find out. How long can tribe to get into the good graces of Arthea so quickly? And if Dhanu and Luka got clear? If that's so, as far as the Chinese concerned, I hope Arthea feeds him to the lions. But the lieutenant and Luka, back there in the world, Tarzan, he told us he'd explain. Well, there's not much to explain, O'Rourke. The idea was Luka. We were to start a fight to draw the guards' attention. So he and Darno could get to the roof of the watchtower and hide until dark. But even if they do succeed in escaping, where will they go? To Rathor, if they get away. I understand that the Shan Rathor, Luka's father and Arthea are enemies have been for years. Luka intends to head the Rathorians in an attack on Tor. Why didn't you let us in on the plan, O'Chat? There was no time. Luka and I agreed on it while we were crossing the bridge from the palace to the wall. Even Darno didn't know. Well, bigari, I hope they make it. Whether they get back here in time to do us any good or not. My, but it's getting warm. Who's climbing at hard work? My, Joe, it is warm. But I don't think it's the exertion of climbing, my dear. No. I think that... Did you hear that? Listen. I don't hear anything, Terry. It's gone now. A rumbling noise like fire, O'Rourke. Just that. Did you hear it? Do you hear the tears again? Yes. Yes, I hear it now. What can it be, Tarzan? Why did it come and go like that? Fire. That accounts for the heat and the smell of sulfur. Why the sound rises and falls, I don't know. It's getting insufferably hot in here. And look, the roof of the passage. There, where it appears to level out. The reflection of fire. A few more steps and we'll be at the top of the incline. Come on. Good. Good heaven. Why, it's a column of fire. It is the home of the devil himself. Look, bars across the end of the passage. We can't go any further. Tarzan and his companions stand, peering fascinated through the massive metal bars into a vast cavern. Roaring, hissing past them, a huge pillar of bluish flame licks hungrily at the roof of the cavern. Above, where the roof forms a natural cone, a square section formed of massive stone blocks. Obviously the handiwork of man may be seen. As they watch spellbound, the monstrous column of blue flame sweeps up scorchingly and licks like the tongue of a hungry dragon. The square section of stone blocks. With a deep rumbling sound heard above the roar of the fire, the center block slides open. The tip of the flame darts up through the opening. Instantly the trap is closed. The pillar of fire drops down past them. Down a hundred feet into a seething, bubbling lake of fire. Past where they stand, rigid with horror, flashes a gigantic yellow figure. One long-drawn dying shriek and the figure vanishes in the fiery pit. Oh, let's get away. Oh, bigurdy. Now I know where we are. That movable block of stone up there. A tears chamber of sacrifice. The heathen idol of gold. Right. This must be the pit of the fires of Thor. The fire we saw come through the floor. And that poor devil that fell down in that... that herald just now. Oh, by the saints. Will he look over there? A natural stone bridge across the pit. From this side to the other. The passage opens on to a wide ledge just beyond these bars. There's another ledge over there on the other side of the bridge. There must be some way of opening this thing. You don't mean... you don't mean we're going to cross this bridge? Behind us, Jeanette. Sheet of the leopard and the yellow men. If we can get through this barrier, cross that bridge. We may find a way out through the passage over there. But... but, Tar, then. The pillar of fire. If it comes up while we're on that bridge. I wouldn't worry about that, old girl. I believe the fire rises only when that stone up there is open. It forms a draft and draws the flames up. Oh, but even if we get across... isn't that another set of bars at the mouth of that passage over there? If we find out how to open these, the others will be easy. There... there must be a lever or... or a handle or something, O'Rourke. Not a thing. Not so much as even a button. I've pushed and pulled at every bar and... Oh, big God, he... he's opening. One of the bars. Which one did you pull? It and I don't know. I... all of them. Those over there must open the same way. We'll find the right one. Come on. We'll leave this one open in case we have to come back. We'll need as best as boots, my friend. At Tarzan. Your bare feet. Let me worry about that, Jeanette. Anyway, the bridge swings round behind the column of fire. Come, we're wasting time. Careful, Jeanette. Here, give me your hand. This thing is no more than a footbridge. Take her out of her hand, O'Rourke. You two go ahead. I'll carry her. You've got to get across in a hurry before that trap up there opens again and draws the fire up. Go on, Ashley. O'Rourke. Oh, big God, he... he storms her as hard as the devil. How do you measure me? Me feet are burning up. Tarzan, look down there into that bubbling cauldron of fire. I never could have crossed it alone. We'll be on the other side in a minute. I'll never forget this as long as I live. We ever get out of this awful place alive. I'm through following Uncle Jim and his... Here we are. The ledge is wider than the one we left. Have you found the bar that opens the gate, O'Rourke? Not yet. I'm hope. Ah, there he is. Oh, come on. And now, where to? On down the corridor. It's wide and well-lighted. Another close cottage. It is an amazing place, this. Honeycombed with underground passageways and caverns. O'Rourke, O'Rourke, undoubtedly. No human hands could have done all this. Well, which way do we go? It doesn't make much difference, does it? These passageways are all alike. He got it. This snake's den seems to be alive with all... Quiet. Yellow man coming. Only two. Here. We'll get behind this projection. They're coming down that cross corridor. You'll see where they go and follow. By the same, will he look, chain together between them to...