Katara led them through the dark and silent streets to the outskirts of the city. It was nearly the same way that he and Asami had come in what felt like a million years ago. Iroh thought it was a testament to how badly the war was going that they had met not so much as a sentry on their way either in or out. Best case scenario, every able-bodied fighter was still engaged with the Northern troops to the east. At worst, when they'd seen UnaVaatu they'd simply fled.

Neither Asami nor Katara had said anything more of their plans to Iroh, and under the circumstances he wasn't inclined to press the issue. Whatever they were going to attempt, his making noise on the way likely wasn't going to help. Besides, he had a lot on his mind, and the quiet was welcome. At some point Asami had re-done her lipstick, and Iroh was practicing the very important task of not being embarrassed every time he thought about it. They walked in silence, the only sound the light scrape of their boots on the trampled snow.

Soon the walls of the city loomed ahead. They weren't high, perhaps 15 feet or so, and were made of thick, solid ice. The so-called South Entrance was in reality just a gap in the wall about 30 feet long that led to one of the city's major thoroughfares. It was a testament to the past 70 years of relative peace that there was no gate, such defenses having long ago fallen into disuse. The two guard posts, one on either side and primarily used for customs purposes, sat dark and abandoned.

As they approached the entrance, Asami slowed. She appeared to be looking for something. She kept jogging off to the side and inspecting the bases of buildings. At the fifth building she turned and waved him over.

"There!" she whispered, pointing to a bundle of what looked to Iroh like thin gray pipes that ran for a dozen or so yards along the ground against a low wall. Asami walked over to the pipes and squatted, examining them. "Iroh," she whispered, "you're up."

He walked over to where she was sitting. "What am I doing?" he said quietly.

"These are water pipes," she said. She leaned forward and used the metal finger of her glove to scrape at the uppermost pipe. The gray coating flaked away to reveal bright silver metal. "Good, they're aluminum. It's common in piping because it doesn't rust, but it also has a relatively low melting point." She looked up at him. "I've seen what you can do. I didn't bring any tools with me, so I need you to cut them."

Iroh frowned. He'd always thought that he might be able to do something like this, given enough time and concentration, but he'd never actually tried. He knew it was possible though; Avatar Korra had practically burned a hole in his ship the last time they'd met, and someone had melted nearly the entire back wall of the Future Industries airplane hangar during the battle with the Equalists. As the only firebender that day chances were good that it had been him, but in the heat of battle the feat hadn't registered.

"I'll try," he said. Asami nodded, then stood and trotted back to Katara, who seemed to be keeping a lookout in the street. Iroh knelt down next to the pipes and examined them. There were five, each about an inch thick, stacked one on top of another and bolted to the wall with small metal fasteners. He closed his eyes and focused, trying to clear his mind. It wasn't easy, but he was grateful to have something concrete to focus on. A lot had happened in the last half hour, and he felt like he was only barely keeping up. He started taking deep, slow breaths to center himself. He pictured a small, bright blue flame, the hottest flame that he could imagine. He held the image in his mind until it filled him. Then he opened his eyes, moved his right hand in a fluid motion towards the pipes, and released.

A six inch jet of blue flame erupted from the tips of his fingers. Iroh held it to the first pipe and got to work.

In the end, he was surprised at how easy it had been. Before long, and under Asami's direction, Iroh had cut free and assembled a large grid of aluminum piping roughly 35 feet long and 12 feet high on the ground in front of the South Entrance. Water dribbled out of the cut pipes in a steady stream and pooled against the wall.

"What now?" he asked, wiping sweat from his brow. Even in the freezing temperatures, cutting the pipes had been warm work.

"Now, you get to be my spot welder. I can do some with the glove, but it'll go faster with two if we're careful." Asami knelt in the snow next to one of the areas where two pipes overlapped. She opened a small panel in the back of her glove, adjusted something, and closed it again. Then she pulled her green tinted flying goggles from her pocket and put them on. "Watch," she said to Iroh, "but close your eyes a little so you're not looking directly at it. And both of you, stand clear. If either of you are touching the metal while I do this, it'll probably kill you." Iroh took two big steps back and saw Katara do the same.

"Good. Okay. Cross your fingers." Iroh squinted as Asami grabbed the intersecting pipes in her gloved hand and squeezed. The area beneath the glove flashed with white light that left a burning afterimage behind his eyes. Wisps of smoke curled around the edges of her fingers. When she removed her glove, Iroh saw that the pipes had been neatly welded together. Asami looked up at Iroh, beaming.

"Honestly," she said brightly, "this glove is wasted on disabling you benders." She then had Iroh repeat the exercise on another intersection using his bending. He wasn't as fast or as neat as Asami's glove, but he found that with enough concentration and force he could also fuse the piping together. They then worked in tandem on the remaining joints, Asami calling an all-clear before her welds so that he knew to stop touching the metal.

Before long they had assembled a passable gate. "Master Katara," Asami said, "I'll need your help to lift it. It's way too heavy for Iroh and I." The old woman nodded, planted her feet slightly apart, and closed her eyes. Then she lifted both hands, first up and then across her body in a swishing motion. At first, nothing happened. Then Iroh felt the ground shake as two enormous spikes of ice surged up from the compacted snow under the aluminum grid. They rose at an angle, the point of each jagged cone sticking fast in between the welded pipes. The ice groaned under the weight of the heavy piping, then slowly began to rise, hoisting the gate with it. Before long, the spears of ice had lifted the gate across the wide opening to the city. The ice retreated, leaving the makeshift gate propped across the entrance.

Iroh stared at Katara in amazement. The old waterbender probably weighed 90lbs soaking wet, yet she'd just lifted what had to be several hundred pounds of metal straight into the air with her bending. She wasn't even breathing hard. It was a forceful reminder that Katara had been not just the wife of the Avatar, but a bending master and elite fighter in her own right, and that though she'd focused on healing in her later years she'd first honed her waterbending skills in combat.

"There," Katara said, rubbing her hands together. She looked to Asami. "Now what, General Sato?"

"Now," Asami said, "we wait for the spirits."

Iroh looked at the makeshift gate, then back towards the south. The moon was high in the sky, illuminating the dark landscape with pale silver light. The black cloud was well out of the mountains now. It moved swiftly across the flat plain of ice that led towards the city, a wide dark stain on a field of spotless white. He couldn't see individual shapes yet, but it was close. At this rate he estimated they had 20 minutes, maybe less.

Iroh studied the gate again, but he couldn't see how it would help them much. It looked woefully thin. With a limited number of pipes, the holes between were more than four feet tall. It would be a squeeze for some of the bigger spirits that Asami had described, but many of them could probably just climb through. Iroh knew that even a simple barrier could slow down a sizeable force considerably, but without a way to effectively fight the spirits as they piled up it would only delay the inevitable.

"Asami," he said, "what are we doing here?" She had moved over to the grid, her back to him now, and appeared to be checking some of the joins. "I don't think this will hold the spirits for long, if at all. And from what you said happened to Tenzin, it seems that at least some of them can fly. The gate may not even hold them for a little bit if they all go over the walls."

"What's your idea then?" she said. She sounded suddenly angry. As Asami turned around he saw with dismay that she was close to tears.

"I didn't mean—" he started, but she cut him off.

"Do you want to die fighting, or would you rather just sit around and let them come?" she snapped. Iroh, who only a short time before had been planning on doing just that, said nothing.

Instead, he closed the few steps between them and gathered her into his arms. He felt her stiffen, then slump against him as he hugged her tight. "Hey," he said quietly, resting his cheek against her head. Her hair smelled faintly of campfire. "Hey, I'm sorry."

"All these people," Asami whispered, her head against his chest. "They're asleep, Iroh, they don't even know. We can't just do nothing." Over Asami's head, Katara gave him a meaningful look. Iroh ignored her.

"Okay," he said. "You're right. Even if we only buy them a few hours, it's worth it." He gave Asami a final squeeze, then released her. Whatever she had planned, it was something he'd be a part of. There were far worse ways to die.

"Tell me what you need me to do."