Charles Sheffield - The Spheres of Heaven

She wiped her wet face. “Tarb, my dear, I hate to spoil your fun and your reunion, but we don’t really need Scruffy inside with us. We need ourselves outside with her. If Friday Indigo or the Malacostracans find her they’re more likely to kill her than appreciate her. Tell her to go back the way she came. Then she can lead the others to us.”

“All in good time.” He was fiddling with Scruffy’s collar. “Here we are. I thought there would be one.”

“Would be what?”

“A message from Deb and Danny. Hmm.” He had removed from the collar a broad silver ring a couple of inches across. He inspected it in the light of his helmet lamp. “Doesn’t look like a message. What is it?”

“Let’s have a peek. Maybe the ring opens up.” Chrissie held it close to her nose. “It’s from Deb all right — see the little entwined DB on the side? But I don’t think it can be a message. It’s a — I think—” There was a soft click. “The outside opens up. Not a message, though. A reel of twine? But this is so thin — you can only see it from really close up when the light is right. Oh!”

“What?” Tarbush craned forward.

“It’s a monofilament strand. Deb used one of these once to cut the head off a man who was trying to rape and kill her.”

“I remember. But why send this to us? If she knew we were in trouble, a gun or a batch of explosives would be more useful.”

“She had to send something small. Something that Scruffy could carry. She tried to give us a weapon, and she has. The problem is, we don’t know how to use it the way she would. And there’s hordes of Malacostracans, we could never take on all of them.” Chrissie was twisting the ring, which suddenly split in two. The thread, almost too fine to see, stretched between two matching circlets of silver. Chrissie took one ring carefully in each gloved hand and spread her arms.

“How long a length do you have?” Tarbush held Scruffy firmly, making sure that the ferret could not get near the danger zone between the two silver rings.

“I don’t know. But the thread is ratcheted inside the rings. I can make it longer or shorter, as I want. Hold something out to me — something we don’t need.”

“I’ll have to put Scruffy down. Do we want to keep her here?”

“I told you, we should let her go.”

“Then hold on a minute.” Tarbush stood and walked over to the air duct. “Go on, Scruff. Find Deb Bisson and Danny Casement.” The ferret hesitated, reluctant to enter the dark, narrow passage. “I said, go on. You found us, that was your job. It’s not safe here for you.”

He held the animal forward again toward the duct. She nuzzled his hand, then vanished in a sudden blur of brown fur.

“Hope she’ll be all right,” Tarbush said as he splashed back toward Chrissie. “Listen to that wind! It’s not nice out there.”

“Tarb, it’s not nice in here .” While he had been gone, Chrissie had removed the compass from the sleeve of her suit. The instrument had provided nothing but nonsense readings since their arrival on Limbo, and now she balanced it on the top of her boot and brought the silver rings carefully down, one held in each hand, so that the thread lay across the compass.

“Careful!” Tarbush said. “Don’t ruin your suit, you may need it again.”

“I know that.” Chrissie bent forward. All her attention was concentrated on the filament, thinner than gossamer, that spanned the distance between the rings. She was exerting hardly any pressure, but the thread was sinking effortlessly through the hardened plastic and metal of the compass. When she paused and delicately lifted the rings, the compass fell into two neat halves.

“Now I’ve got the feel of it. The question is, will the monofilament do the same thing to the wall?”

“Even if it can, how does that do us any good?” Tarbush picked up the halves of the compass. “To cut something apart, you have to place the rings on both sides of it. We’re inside the wall.”

“So we have to be tricky.” Chrissie stood up and went across to the closer of the ventilators. “Before I waste any time, let’s see if there’s any point in even trying.” She reached far inside the duct, her hand still holding its silver ring. She brought the other hand around in a semicircle, so that the monofilament met and cut into the perimeter of the duct. A crescent slice, carved from around the wall, silently slid free and splashed into the dark water at her feet.

“Principle established,” Chrissie said softly. “This will cut anything. Now for the tricky bit. I have to widen the hole more and more, and hope I can get one hand all the way to the outside.”

“Chrissie, let me do it.” Tarbush held out his hand. “My arm’s longer than yours, and stronger. I can reach outside easily.”

“You could — if you could get that great ham fist into the duct at all. Which you can’t. Stand clear, sweetheart. Keep your light focused on where I’m cutting. I don’t want to start slicing pieces off my own arm.”

She was moving one hand in a wider arc, excising from the wall a circular cone half a meter across. As it came free, Tarbush lifted it clear. “Hm. This is warm ,” he said. “That thing you have isn’t just a monofilament. I wondered how it could cut so easily. There must be nanos inside the thread, freeing molecular bonds.”

“Deb specializes in tricky weapons. But now for the hardest part.” Chrissie had her arm in the enlarged hole up to the shoulder. “I can reach all the way through, but I have to enlarge the duct at the outside edge because unless I do that we have nothing useful. I’m going to work one hand outside, hold the ring against the outer wall, then slide both hands in unison to slice a cylindrical section. Don’t breathe.”

“I’m not sure it’s necessary to go to all that trouble.” Tarbush had been examining the conical wedge removed from the wall, and now he moved forward.

“We want to get out, don’t we?” Chrissie, her hands encumbered with the rings, could not easily push at him. She said sharply, “Get your hand out of the way. If you stand like that you’ll lose some fingers.”

“No. Back off, Chrissie. I need to try something.”

“Tarb!” But he was dangerously close to the monofilament, and she was forced to pull her hands clear. “What are you playing at?”

“Just watch. We haven’t used my strongman act for years, but let’s see how it plays on Limbo.” He stood in front of the ventilator pipe, took a deep breath, and punched his fist deep into the expanded hole that she had made. Chrissie heard nothing, but she saw a cloud of powder fly out around his arm.

“What did you do?”

Tarbush was pushing his shoulder and then his head into the hole. “Take a look at the piece you cut out.” He was grunting at some great effort, interspersing his words with gasps. “Push your finger in it — you can, it’s soft as cream cheese. This whole building must have an — integrated structure. Very strong when it’s complete, forms a single unit, but if any part is — destroyed — the rest is ready to crumble. We’re lucky that Deb’s — monofilament cutter didn’t bring — the whole place down on top of us. But we have to move fast — it’s self-repairing, and it’s starting to adjust. Going to be touch and go. One more push — hah! — I’m through! My arm’s outside. Now for the big push. Look out back there.”

He emerged from the hole, coated in gray powder and coughing and choking. “Should have closed my suit — up my nose — going to sneeze.”

He did, in a vast explosion of air loud enough to hear above the sounds of the storm. Then: “Follow me! Close your suit. It’s a mess outside.”