The Hunt of the Wolf and the Serpent

As soon as both their captive and Zai were in his little underwater room, Kano sealed the entrance, melting the ice of the slide from the bottom up, allowing the air from within the tube to escape soundlessly up it. If he'd done it the other way around, it'd have trapped the air underwater and it would have risen with enough noise to attract some serious attention.

"Wh-...Who are you two? What are you doing here?"

"People." Kano said, answering the man. He folded his arms. "And the question is, what are you doing here? What is this place?"

Kano looked around at Zai as he spoke.

"Secret factory means weapons with illegal purposes in mind." he said, his arms still folded. "If they are building invasion forces, I need to know. My people need to know. Our alliance with the Fire Nation would put us at risk if they chose to attack the Earth Kingdom. And if they attack the Air Nomads or the Southern Water Tribe, well... Let's just say my enemies would become anyone wearing red real quick."

He looked down at the unconscious figure of the worker on the ground.

"Let's have a look and see just what kind of secrets this place is hiding..."

Kano executed a short, fluid movement and the ice liquefied. He brought the water in around them and froze it into a platform. He stepped up onto it with Zai and the unconscious man. He then made it slowly push them upward toward the surface, maintaining a bubble around them, mostly for the benefit of their captive. The two of them could hold their breaths for quite some time... or, at least, Kano could. Zai seemed the sort, though. In any case, soon enough their icy pillar hard pushed them to the surface of the pool. Kano extended an ice bridge toward the dark rocky wall. There were plenty of nooks and alcoves there where they could hide their Fire Nation friend before continuing.

"So," Kano said once they finished situating the unconscious man. "Where do you think we should start? Personally... I like the look of that shack up there. Looks like a foreman's quarters or something important."

He was indicating a small building situated at the opposite end of the cavern. It was situated near the ceiling and had a large window which looked down onto the factory's many structures above. He could see a small ridge running along the outside of the cavern wall which would allow them to skirt the edge of the compound with minimal risk of exposure...