Sera, Yazeed, Luca, and Franco were going to follow the tributary on the west side of the room to the old pipe that ran above the treasury vaults. The rest of the Black Fins would stay where they were and wait for the four to return.
Yaz and Franco put their crossbows down. They were still carrying torches and had pickaxes slung over their backs; the tributary’s tunnel was too narrow to allow the weapons, too.
Sera started for the channeler, her crossbow raised, when Yazeed suddenly grabbed her arm. He pointed wordlessly, but she’d already seen what had spooked him. A watchman had entered the room. He swam to the channeler and bent down to examine a glass-covered dial, his back toward them.
The Black Fins had prepared for all eventualities. Sera nodded at Silvio, her best marksman. He raised his crossbow and a split second later, a dart found his target’s neck.
The watchman gave a surprised shout of pain. The dart’s tip was filled with weak stingray venom. Full strength, the venom would kill a mer. Diluted, it only put its victim to sleep. Silvio caught the watchman as he fell backward, his eyes already fluttering closed.
“Nice shot, Sil,” Yaz said, racing by him. Franco and Sera were right behind him.
As two other Black Fins dragged the unconscious merman over to a closet, Silvio cast an illusio spell to transform himself into an exact double of the watchman. He would busy himself checking dials and valves in case Vallerio’s soldiers decided to patrol the lava chamber.
Sera, Yaz, Luca, and Franco swam into the west tunnel, hugging their tools and weapons close to their bodies, and followed it upward. Lava globes, spaced ten yards apart, illuminated the tunnel. Each had a hook underneath it to hold maintenance workers’ tool bags. Unable to move their tails vigorously for fear of smashing the globes or getting caught on the hooks, the four lost speed. They’d hoped to reach their target destination in five minutes, but it took them nearly ten.
“I see it,” Franco finally said, pointing above them to where the main artery split into two. One section of pipe continued straight up into the palace. Another ran due west above the treasury vaults. “We’re behind,” a tense Yaz said as they reached the join. “The lightworks show is going to start soon.”
“There’s the valve,” Luca said, pointing at a bronze handwheel jutting out just past the join. “All we have to do is rip a hole in the old pipe, then open it.”
“Easier said than done,” said Yaz, holding his torch up to the tunnel that contained the west-running pipe.
The tunnel snaked horizontally through the rock foundation and was much narrower than what they’d just swum through. Small blue crabs clung to its top; they scuttled away from the torch’s light. A thick layer of silt lined its bottom.
Franco was the slimmest of the three mermen. He entered the tunnel’s mouth and started to swim through, holding his torch in front of himself. When that didn’t work, he crawled…until he got stuck.
“I can’t move!” he called out. “Yo, pull me out!”
Yaz and Luca grabbed his tail fin and yanked. He came out covered in silt.
“I’m the smallest. I’ll go,” Sera said.
Her nerves were as taut as a bowstring as she entered the tunnel. She was worried about getting stuck in the small space, but excitement overrode her misgivings. They’d made it this far. They might actually do this if she could just break the pipe.
Yaz handed her his pickax. “Swim about ten yards in, then rip open a good-sized hole,” he said.
Sera made her way down the passageway on her back, holding the torch and pickax on her chest and pushing herself along with her tail. Silt swirled around her, making it nearly impossible to see.
When she got far enough down the tunnel, she waited for the water to clear. There was so little room to maneuver that she had to extend both arms above her head and swing the pickax from her shoulders without bending her elbows. Within minutes her muscles were screaming. Gritting her teeth against the pain, she forced herself to swing over and over again.
The pipe was made out of goblin-forged steel, strong enough to resist the extreme heat of lava, but it was centuries old and corroded. Finally, just when she thought she couldn’t swing the ax one more time, Sera heard a satisfying metallic screech as its blade punctured the pipe. She gave a victory yell and swung again and again, ripping at the hole’s edges until it was big enough. Then, spent and shaking, she wriggled back down the tunnel. As she crawled out, her excitement dimmed. She’d realized they had a problem. A big one.
“I was able to rip the pipe open, but that doesn’t change the fact that the tunnel’s super narrow,” she informed the others. “Even if we manage to get into the vault, how are we going to get any treasure out? Most of the fighters won’t be able to squeeze through.”
This was the Black Fins’ one and only chance to get into the vaults. Their break-in would eventually be discovered and Vallerio would make sure it could never be repeated.