Free Tunnel of Secrets by Franklin W. Dixon

wasn’t sure how much time we had before we reached where they were taking us. I wanted to know what had happened with the sinkhole and what this Grandmaster had to do with it.
    “So what’s the deal with stealing the Admiral’s key anyway? You guys almost killed me twice trying to nab it.”
    “Yeah,sorry about that,” Keith said, not sounding very sorry at all. “But your showing up at the last minute messed with our plans, so we had to ditch you. The tunnels weren’t supposed to cave in like that. Someone put one of the explosives in the wrong place.”
    Keith whacked Scott on the back of the head.
    “Ow! Jeez, Keith, I said I was sorry.”
    “Wait, so you guys created the sinkhole that swallowed the Admiral with a controlled demolition?” Frank said in disbelief. “That’s like a crazy feat of engineering. If one thing went wrong, you could have brought down the entire square.”
    “Yeah, the Grandmaster is a genius. He designed the whole thing himself,” Keith gushed. “He had the tunnels all mapped out and knew exactly where to set the charges. He could even identify the statue’s weak points so I could cut off the key superfast. I would have been back here with it before the smoke cleared, but I got caved in and then you showed up again.”
    Keith couldn’t resist giving me another jab with the cane.
    “What can I say?” I said. “I have impeccable timing.”
    “I wouldn’t be so sure about that,” Keith said ominously. I could practically hear him smirking as he led us into an open space that looked like an underground coliseum carved out of stone.
    Three balcony levels wound their way around the chamber’s circular walls, looking down on a main amphitheaterbelow. Each level was lined with stone dwellings of different sizes. Some of them had portals for windows and looked like they might be ancient dorms or apartments. Others had iron bars and looked like cells.
    More masked figures had gathered around a creepy-looking altar at the center of the amphitheater. Behind the altar were steps leading to a large stone vault with a giant keyhole. The keyhole looked just the right size and shape for the Admiral’s bronze key.
    A large eye was engraved in gold over the vault, and something was written under it in another language. Frank took a moment to translate it.
    “It’s Latin,” he whispered. “It means . . . Sacred Temple of the Secret Order of the Knights of the Bay.”
    “I think we found the Secret City,” I murmured back.
    “Tell the Grandmaster we apprehended two spies trying to infiltrate the city through the South Wall,” Keith ordered the others, who immediately scattered.
    “You!” He pointed to the shortest one in the group. “Come here. I need you to help escort the prisoners to their cell.”
    With Keith momentarily distracted and Scott busy trying to scratch his face under his mask, I saw our chance. I quickly made eye contact with my brother and gestured at the chain running from our shackles back to Scott’s free hand. Frank got it right away, and we both yanked as hard as we could at the same time.
    Scott yelped, falling onto his butt as the chain flew out of his hand. We took off running . . . which would have been a lot easier if we hadn’t still been shackled together with a chain dragging behind us.
    “Stop them!” Keith yelled.
    We knocked over the short one, who had been standing frozen in place, and lowered our heads to bowl over another one like a two-headed running back. We might have made it too, if Keith hadn’t managed to grab hold of one end of the chain. We tumbled into a heap on top of the ghoul in front of us and found ourselves staring at the end of Keith’s cane—which now had a retractable blade sticking out of it.
    Behind Keith, the short one we’d knocked over was still on the ground, fumbling to pick up a mask that had been knocked off in the scuffle, which allowed me a good look at its face. Or I guess I should say her