"Down the center? The keel, you mean? We just left that."
"No, the center. The gas bags are probably doughnut shaped and if they are, there will be a catwalk right through the center, from nose to tail. Somewhere along it, there should be a ladder going up. And there should be at least one other catwalk along the top of the gas bags."
"You make this thing sound like a floating briar patch."
"Most dirigibles were. Let's just hope Brer Thrush doesn't spot us and follow us in."
The blob of light was bigger now, and they could see a second one further down where the shell started curving in toward the nose. Soon they reached the first area of light. It was coming faintly from the open space between tow gas bags.
The two agents halted, and Illya peered cautiously around the main-frame girders that marked the division between the bags. After a second, he moved quickly across and motioned Napoleon to do the same.
Napoleon glanced around the edge of the bag and quickly joined Illya in the shadow of the next one. "It looks like a bicycle wheel for the Jolly Green Giant," he remarked as they moved on.
"It works on somewhat the same principle," Illya replied. "Those wires do most of the work in holding the ship rigid."
A swaying motion cut off any further information. "Going up," Illya announced. He stopped, took the knife from his pants pocket, braced himself against the lighter girders of one of the intermediate frames, and sawed a slit in the outer fabric. Returning the knife to his pocket, he widened the slit with his fingers and peered out."They have most of the mooring lines loose," he said. "We'll be on our way any minute."
Napoleon gave Illya a hand in getting back onto the catwalk. "Can we find those valves soon enough?" he asked. "El Presidente's palace in Cerro Bueno isn't too far from here, as the dirigible flies."
"If we don't find them, we can start cutting holes in the bags."
The agents started along the catwalk again. They passed another main frame, this one unlighted, and then came to the second blob of light. As before, Illya peer cautiously around the corner before crossing the lighted area. As then moved ahead again, he whispered over his shoulder, "That's probably the light above the control gondola. Any ladders from the center to the upper catwalk will probably be there."
Napoleon remained silent. As they continued moving forward, the curve became more pronounced and soon they were surrounded by darkness. The agents slowed their pace and Illya made sure of his footing before each step.
"At this rate," Napoleon said, "our friends will be over Cerro Bueno before we find the nose of the dirigible."
"Lead the way, if you want to move faster," Illya retorted. "Just remember, this thing has just made its first flight in over thirty years. I want to be sure the catwalk is really there before I step on it."
Another tremor silenced them. Illya paused to cut another slit and peer out for a second. "They're lifting," he announced.
At that moment the engines came to life, and the agents could feet the gentle forward movement that passed for acceleration in a dirigible. They moved along the catwalk again until they reached a main frame which apparently coincided with the location of the control gondola. Here there was a ladder, running from the keel to, they hoped, a catwalk at the top.
Illya inspected the ladder briefly, then stepped out on it and began to climb. Napoleon followed.
"We aren't likely to run into any crew members, are we?" Napoleon asked. "I feel somewhat exposed out here."
"Not likely. There's very little need to inspect the gas bags in flight, normally, and since they seem to be running with a skeleton crew, they'll probably have little time for such niceties."
The climb took less than a minute and was relatively quiet. Now that the dirigible was moving forward, the tremors had subsided and the upper catwalk seemed a steady platform. They could see a single, dim light bulb glowing about a hundred feet toward the stern. The outer covering was visible through the girders only a foot over their heads.
"What do these valves that we're supposed to be finding look like?" Napoleon asked.
"My dirigible lore doesn't go that far. Presumably they look like valves. They'd have to be pretty big—perhaps several inches across. And they would have to be attached to either electric wires or control cables so they could be operated from the control room. Electric operators would be my guess, but I couldn't say what a German engineer in the 1920's would pick. They should be located fairly close to the catwalk so they could be inspected."
"If they're very far from that light just ahead, we're going to have to feel for them."
"If we don't find them soon, we can start stabbing at the gas bags, and— Did that light flicker just then?"
As if it had been waiting for them to give it a cur, the light went out. Both agents froze in their tracks, then slowly turned to look back along the catwalk. There was not even a distant glow.
"Why should they black out the ship in flight?" Napoleon asked.
"They don't normally. Must be an electrical failure. Can you hear the engines?"
Napoleon listened form a second. "I think so. If the failure is in the control gondola, do you suppose the OTSMID is dead, too?"
"We'll see. Don't jar me in the next minute," Illya said. There was the sound of metal on metal, then a series of cutting noises.
Illya's voice came again. "There's no light at all outside, and the moon was out when we got in here. The OTSMID must still be functioning."
Napoleon thought for a moment. "We'd better give up on finding the valves. Let me strike a match and we'll see about puncturing a few gas bags." He pulled a battered matchbook from his pocket, extracted a match, carefully felt for the striking surface, and deftly scraped the match head across the surface.
Nothing happened.
Muttering about Central American matches, Napoleon located the striking surface again, in preparation for a second attempt. Just as he touched the match to the striking surface, pain shot through his fingers. Stifling a yell, he dropped it and shook his hand violently.
"That thing was lit!" he exclaimed in a hoarse whisper.
"Lit?" Illya's voice came from a foot away. "You're sure?"
"My fingers are sure."
Illya thought for a second. "I'm tempted to ask what does it all mean, but I suspect that I know."
Napoleon agreed. "The OTSMID is working and the nullifier isn't. Does that suggest anything to you?"
"It suggests we aren't going to locate the gas valves."
Napoleon considered the situation. "I think it's worth a gamble. If the nullifier comes back on, the chances are that we will either be in control of the ship, or we won't have gotten far enough along to be trapped. And if we could get control of the ship..."
"Let's get moving, then. Reaching the control gondola without seeing it will be a problem. Keep feeling for that ladder; if we miss it we're stuck up here." On their hands and knees, the agents crawled along the catwalk, feeling the empty space to their right every few inches to make they could touch the ladder when they came to it.
Once they reached the ladder, it was no more difficult to descend in the total blackness than it had been to ascend in the light. As they reached the relatively firm footing of the keel, they could hear the buzz of excited conversation coming from the area of the stern. Over of the general turmoil, they could make out two or three voices coming from almost directly beneath them. No words could be distinguished.