Bolin

"Left a bit! No, right a bit! A bit more- no, that's too far!"

Bolin watched as earthbenders rolled a bombard into position behind a wall of packed earth. The machine was a new invention that Varrick had invented and the Earth Empire used, consisting of a barrel on wheels with an opening on one end. A spherical rock would be inserted, and then it would be fired out of the end towards the target using the force generated by at least two earthbenders and a cylinder of compressed air. Together, this gave the weapon a much greater range and allowed it to hit much harder than any one Earthbender flinging rocks under their own power could achieve.

Bolin watched as more followed the weapon, hovering boulders in midair that they began to pile up beside it. Still more carried large canisters.

"Hey! Bolin!"

A voice called his name from behind him, and he turned to see Zhu Li running up behind him.

"What?" Bolin folded his arms and glared at the woman. She had war-profiteered just as much as her boss had, after all.

Zhu Li stopped in front of him. "Kuvira wants you," she explained. "We're about to open fire."

Kuvira had parked her train on a slightly raised area of ground, and was using it as a command post to oversee the progress of the siege. It had been slow going thus far, which was why Kuvira had decided to use the compressed-air cannons.

"Alright, I'm coming now," Bolin told her, and followed her back up the hill towards the train. Technicians stood around it, poking around the wheels as more ran down the hill to perform last minute maintenance on the cannons.

Zhu Li reached up and opened the hatch, before pulling a set of steps down so they could climb up into the vehicle. They were greeted in the entrance by Baatar.

"Bolin, you're here! Just in time too."

"Nice glasses by the way," Bolin observed, and it was true. For some reason Baatar was wearing a pair of sunglasses. "Are you trying out a new fashion?"

"Something like that," the man replied, and handed him his own pair. "You might want some too."

The three of them went into Kuvira's office, where a large window allowed them a clear view of the fortress and the siege works. The Great Uniter herself stood with her hands behind her back staring intently out of the window, silhouetted against the mountain and the sky. Varrick, meanwhile, fiddled around with a strange device in the background.

"We're all here," Baatar told them.

"Excellent," Kuvira turned around, and Bolin saw she was wearing sunglasses as well.

"I never thought you wore sunglasses!" Bolin told her.

Kuvira smirked at that.

"I can wear sunglasses," she told him. "Sunglasses are cool. Speaking of which, you might want to put those on. We're just about to begin."

Bolin didn't know why he needed to put the glasses on, but he complied.

"We're almost there!" Varrick said, as his device began to beep. Bolin watched as the cannon were set level. Hatches at their rear were opened, and canisters of air were slid inside, before earthbenders lifted boulders and rolled them back down the muzzle.

"I don't know if we're about to make history," Bolin heard Kuvira say, "but we are about to change the geography."

Bolin wondered what she meant by that, but didn't have much time to think about it.

Outside, the guns were lifted again so their barrels pointed high into the air. Two earthbenders walked forwards so they took position on either side of the front of the cannon and then dropped down into a horse stance.

Nothing happened for a couple of seconds. The air was still, and Bolin could feel the anticipation in the others.

Finally, a third crewman walked up to the rear of the cannon, and signaled the earthbenders. He made to press the button to release the air when-

Suddenly, the sky was purple. Even with the glasses, Bolin had to close his eyes as an incredibly bright purple light filled the air, and he could feel the heat even through the glass. A moment later, a deafening buzzing noise followed.

The heat died away, and the noise faded. Bolin opened his eyes. The artillery crews were lying on the floor, having been knocked over by the force of the blast. Several of them were clutching their ears. Even the guns had been physically moved backwards a few inches, and the piles of ammunition had been knocked over. He turned to Kuvira, but his question of "what in the Spirits was that?" Died in his throat when he looked up.

Shanbao fortress was gone.

Where once had stood the mightiest fortress in the earth Kingdom, there now stood a mountain much reduced in size with a large flat plateau at the top.

"Excellent," Kuvira said, clapping her hands together and seeming completely unfazed by the whole thing. "Well done Varrick, it worked better than I could ever have dreamed!"

"Did it?" Varrick looked down at his device, which had stopped beeping. "Good."

But he didn't sound sure.

"What was that?" Bolin finally found his voice. "And why didn't you tell me?"

"Oh, sorry," Kuvira apologised. "But we had to be sure they wouldn't find out what we were up to. Better if they didn't know what hit them. That's why we set up that artillery bombardment. If they found out that we were about to attack them, they would assume those-" she gestured to the artillery outside, "-would be what we attacked with. So those were just a decoy."

"So what did we attack with?"

"We tunnelled into the mountain, put Varrick's spirit vine device right under them, and then overloaded it with energy. Turns out it makes a great bomb!"

Kuvira was sounding entirely too pleased with herself as she walked over to her desk.

"Anyway, that means the pretender King won't be a problem any more! Ladies and gentlemen, today is a day we have waited for for years."

She pulled out a bottle of alcohol, poured some out into glasses, and handed them around.

"We can go home at last," she declared. "Mission accomplished!"

Nobody except Baatar cheered very enthusiastically.