Their voices are dimming, and I can finally exhale. Cautiously, quietly, I resume moving downstream through the cold water. They spoke of a boat, which means there must be a place where the boat goes, and that, in turn, means the stream must have an exit. I just have to find it.
I stay to the center, where the streambed is more level. I don’t dare to turn on my headlamp, but the bioluminescence in the water creates a glow each time I step forward, and my legs have swirling trails and coils of green light around them. When the tunnel takes another bend, I pause, blinking into the darkness ahead. I step sideways until I can lean my shoulder against the wall. Then I prop a knee under Dubbs’s legs and get a hand free to turn on my headlamp again. It helps, a little, but I have no real way to tell how far I’m going. I make it around the next bend, and another. At first, the water is shallow, but the farther I go, the deeper it gets, until it’s as high as my butt. Walking with the current is treacherous. I keep trying to carry Dubbs higher, but I can feel the water dragging at her toes and her gown.
As I make it around the next bend, another dark length of tunnel stretches before me with no end in sight. A flurry of warning swirls up in the back of my mind again.
“Stop that,” I say aloud.
I’m stressed out enough on my own already without some invader in my brain adding even more anxiety. I can’t go back. That’s not an option. I search the arching ceiling and walls for any hint of an exit. What I find instead is a narrow stone ledge that runs along the right side of the stream, like a pathway. Hopeful, I scramble up the ledge with Dubbs, and pull her close again. My wet scrubs cling to me, and she’s not much drier. We’re both shivering. I take a step, testing to see if the dark stone is slippery, but it’s not.
For the first time, we can make real progress. The ledge takes us around another bend, and I have to step over a large pipe that sends a gurgling waterfall into the stream. Then the ledge meets a low archway over the stream and ends. The water looks deeper, the current stronger. We’re stuck.
Gently, I crouch down and lower Dubbs to my knee. To see her shivering in her sleep is alarming. My arms ache from carrying her and clenching her tight, but I try to rub some warmth back into her.
Then I lean over to look through the archway. Ahead, to the right, the stream takes another turn, and I’m doubtful. The lowness of this arch would make it difficult for a boat to pass beneath. I glance back the way we came, and then I see it: a long, narrow skiff tied up on the other side of the stream, opposite the large pipe with the waterfall. I went right past without seeing it, but now I can make out the stone landing and a narrow archway with a stone staircase leading up.
That’s it. We just have to cross the stream and we’ll be able to escape. I’m sure of it. Just then, a dark, long shape glides through the water below me and swims under the arch to my right. The bioluminescence flows in a green trail behind it and swirls as it fades. I shiver again, watching to see if the fish will return. The water under the arch remains dark and undisturbed, except for the subtle, flowing ripples on the surface.
“Is that what you tried to warn me about?” I ask.
A dim affirmation flickers in the back of my mind. It’s almost as disturbing as the fish itself.
Carefully, I lift Dubbs into my arms again and backtrack along the ledge. I climb back over the water pipe. On the opposite side, slightly upstream from the arch, the landing we need to get to is probably a good six strides away through the water. At my feet, the stream has its normal flow, with only the faint, random green glimmers, and it’s hard to tell how deep it is.
A racking shiver runs through me. I can’t put this off.
I slide in up to my thighs and step carefully toward the middle of the stream. My pants legs light up with bioluminescence like before, and each step takes me a bit deeper.
I’m halfway across the stream when an ominous gurgle makes me look toward the arch. A black-and-green streak is swimming swiftly through the water right toward me. I shriek and plunge ahead through the stream.
The fish races closer.
My foot slips and I stagger, pulled down by my sister’s weight. She dunks into the water.
Charged by terror, I pull her up and lunge forward again with all my strength. I leap for the edge of the landing, roll onto the stone with Dubbs, and get my feet out of the water just as the black thing skims beneath us.
Teeth snap. The water churns.
But we’re out. My heart’s pounding. I can barely catch my breath. I clutch my sister tight, and back against the wall. In the beam of my headlamp, the thing slowly circles in the water. Green bioluminescence scatters and twirls in mini whirlpools. One wicked, cunning eye rolls past us, getting a good look.
“We made it,” I whisper. Then I raise my voice, defiant. “You didn’t get us, fish.”
We’re soaked, cold, and terrified, but we’re alive. Another shiver ripples through me, shaking every bone until my teeth chatter.
Dubbs is shivering in my arms, too. She has a bleeding scrape on her wrist and her gown is drenched, but she’s breathing. I hug her to me and kiss the top of her head.
“I’ve got you,” I say fiercely. “Don’t worry.”
I wipe the wet hair out of my face and look up at the stone staircase. Since the skiff is here, this must be a real route in and out of the vault, which is promising in terms of seeing daylight again, but it’s also possible that one of vault doctors could be waiting at the top.
Still, what other choice do I have? I’m not going to take the skiff back upstream and try to find a different way out.
Okay. Here we go, I tell myself.
Taking a deep breath, I hoist my sister into my arms once again and approach the staircase. My headlamp casts a cool beam along the rock. The first few stairs lead straight away from the water, but soon the staircase twists and spirals upward through the stone. Dubbs feels heavier than ever, but I keep going, bracing my left elbow against the wall to steady me with each step. A faint breeze touches my cheeks, and then the flavor of the air becomes lighter. Fresher.
The stairs stop at a flat landing with an old ladder, and looking straight up a shaft where the ladder goes, I see a hint of light. Two hints, actually. Two distant circles of light.