The waterfall itself is not nearly as tall as it had felt while plummeting down its length last night. It kicks up a huge spray that moistens thick layers of moss on the underside of the waterfall’s overhanging rocks. Although there is no sign of the boat, a few of our bags are afloat and pressed up against the side of the plunge pool.

“Check those out!” Ben says, pointing up.

Stalactites cone down from the ceiling hundreds of meters above us, hanging like fanged teeth, sunlight glazing them reddish orange. Interspersed between the stalactites, vines dangle down like stringy food caught between teeth. Huge towers of calcite lift off the cave floor at leaning angles, and ferns and palms rope themselves around the base of these towers. Thinner stalagmites rise fifty meters tall, but it is the sheer gargantuan size of the cave that bedazzles us the most.

“You could fit a city in here,” I yell, wanting to be heard above the din of the waterfall. “Skyscrapers twenty, thirty stories tall. Whole city blocks a mile long.” Nobody responds; nobody hears me. I move away from the waterfall where it’s quieter.

The others follow and we gather in a large column of sunlight. The warmth is glorious. The sunlight bleaches our skin, makes us glow with a nuclear effervescence.

“Now what?” Epap asks. All heads turn to Sissy.

“We explore,” she says.

“Is this it?” Ben asks. “Is this the Land of Milk and Honey, Fruit and Sunshine?”

“I hope not,” Epap says, shaking his head. “This place is the dumps. I’d take the Dome over this, actually. I haven’t seen any milk, honey, or fruit. There’s sunshine, drips of it, anyway, but we had more back at the Dome.”

“This is what we’ll do,” Sissy says. “We break up into two groups. We look for a clue, a sign, anything. The Scientist must have left us something.” She looks around, then hikes into the depths of the cave, Ben and Jacob in tow.

“All right, you two,” Epap says to David and me. “Let’s go this way. Eyes peeled, guys.” We head off perpendicular to Sissy’s direction, along the bank, following the river.

Hours later, there’s nothing to show for our efforts. The terrain makes walking difficult, with loose rocks seemingly designed to sprain our ankles scattered everywhere. David, Epap, and I proceed slowly, not wanting to miss anything, but we spend most of the time with eyes fixed in a narrow cone of vision on the ground, negotiating around stones and slippery moss. And though we’re heading toward what we hope is the cave’s exit, after two hours, there’s still literally no light at the end of the tunnel. If there even is an end. The river plunges down into a succession of large bowls at three different tiers, the descent steep and treacherous. Several times, we have to sidetrack considerable distances to get around huge boulders. We slip often on moss-laced rocks, our hands flailing wildly, grabbing at towers cloaked with flowstone and at tall rocks with scalloped surfaces. Eventually, our path is completely impeded by a wall of fluted limestone, massive and algae-skinned, ten stories high. The river snakes through a relatively narrow opening and into another tiered series of waterfalls. We head back, bodies hunched over with fatigue, starvation, and discouragement.

The other three are sitting in a column of sunlight near the waterfall when we return. Judging from their drooped shoulders and dour faces, they haven’t fared much better. They hand us our share of lunch: a few berries they’d found that we scarf up eagerly.

“So much for the Land of Milk and Honey, Fruit and Sunshine,” Epap says. “No food, no milk, no honey. Not even any wood to burn.”

“We should head outside,” Jacob says. “Follow the river out.”

“We just did that,” I reply. “Tried to, anyway. It’s farther and more difficult than you think.”

“It’s our only move,” Jacob says, glancing at the waterfall. “We can’t backtrack—we’d have to climb up the sides of this waterfall, and they’re way too steep and slippery. But we can’t just stay here, either. We need food. We should leave now.”

“No.” Sissy says this without looking at us. “We stay here.”

“Sissy—” Jacob begins to say.

“Look! I’m staying,” she snaps. “You go if you want. I’m staying.”

Jacob clams up, hurt shooting into his eyes. “I only meant—”

“I’m not arguing with you, with any of you! There’re only two things we need to do, okay? Find some kind of sign left by the Scientist, and keep Gene alive. Is that simple enough for you to understand? This is our life distilled down to its rawest elements right now. Find a sign, keep him alive. Two things, people.”

We sit stunned by her outburst. She walks away, her chest heaving, disappearing behind a large boulder.

I follow her. She’s staring into the waterfall, arms crossed against her chest.

“Hey,” I say, as gently as I can. I step through a short narrow pathway between two boulders.

She doesn’t reply, only bites her lower lip, just half of it; the other half loops out in a fat curl. Her eyelids shut halfway, and a tear spills out that trails down over her cheekbone. She doesn’t turn away as I thought she might. Her hand rises—to wipe the tear away, I think—but stops in front of her lips. She half-cups her mouth, her fingers quivering, her lips collapsing. Now she turns away from me, just as I see her face breaking.

The pressure has gotten to her. The burden of all their lives carried squarely on her shoulders alone.

I place my hand on her. She doesn’t move away as I thought she might, but leans into my hand, the curve of her shoulder fitting perfectly into the cup of my hand. Her flesh is soft, but there is a fierceness in it, too, in the thin coat of hard muscle and the solid protrusion of jutting shoulder bone. She turns and looks at me with a fierce intensity. It is the kind of attention my father taught me to always avoid. Eye contact meant you were at the center of a person’s attention; get out of it, fade out of it, move away.

But I cannot look away. I never realized how aquiline and beautiful her eyes are.

“I feel like I’m failing everyone, Gene.”

“You’re being ridiculous. We’d all be dead by now if it weren’t for you.” I move closer to her until I can feel heat thrumming off her body. “I’m with you, Sissy. I want to find him as much as you do. If not more.”

For a moment, something swims across her eyes that is yielding and soft.

It’s too much for me. I flick my eyes away.

We don’t speak for a few seconds. Then she shakes her head. “I feel like I’m missing something obvious,” she says. “Something he’s left behind. A clue, a sign. Something right under my nose. Like the games he used to play with me.”

A strange jealousy rises in me. So he had played the same game with her. I thought I was the only one.

“Everything okay, Sissy?” It’s Epap on the other side of the narrow passageway. Sissy pulls away from me as Epap slides between the boulders.

“Is everything okay?” he asks again, peering intently at her.

She wipes quickly at her tearstained cheek. “Fine,” she murmurs and brushes past him. She slips through the narrow passageway.

Left alone with me, Epap gives me a sharp look. I tuck my head down, walk by him. When I return to the group, Sissy is already sitting next to Jacob, ruffling his hair, smiling. Jacob laughs.

We’re too tired to move. The beams of sunshine have held up so far, but there’s no telling how much longer they’ll last.

An hour passes; a few of us drift off to sleep.

Sissy suddenly sits up. “Oh, so stupid!” she says, smacking her forehead.

“Sissy?” Epap says.

She doesn’t reply, only walks toward the waterfall. She steps carefully on the wet bedrock around the perimeter of the plunge pool. One slip into the pool so close to the waterfall, and she might find herself pinned underwater by a deadly undertow.

The other boys are waking up now. “What’s she doing?” Ben asks.

Pressed up against the wall to the side of the waterfall, Sissy pauses. Then she steps forward and disappears into the curtain of water.

“Sissy!” Ben shouts, and in the next second we’re all rushing over to the waterfall. Ben is beside himself with worry and it takes two of us to hold him back. We peer anxiously through the heavy sheets of crashing water.

“There!” Jacob yells, pointing to the side of the waterfall where the curtain of water is thinner and frayed.

She is a hazy blur behind the cascading sheet of water. Her arms stick out first, then her head, hunched down against the pummeling water. When she’s pushed through, she’s completely drenched. But she’s smiling with the widest, most sparkly grin. “You guys coming in or not?”

“Huh?” Epap says.

“C’mon, don’t be so scared,” she teases. “I found a cavern back here.”

“Hold on, Sissy,” I say. “How do you know we’re supposed to go in there?”

“Just a guess,” she says, laughing loosely. “And maybe because I found a whole set of dry clothes and a rope ladder leading away.”

It’s dark in the cavern. Only a single hazy column of sunlight illuminates the interior. Our clothes are soaked through, and already we’re starting to shiver.

“About those dry clothes you mentioned…” I say through chattering teeth. Sissy smiles, takes us to a basket hidden in the shadows. There’s enough clothes for a dozen people of varying sizes.

“How did you think to look behind the waterfall?” I ask her as we change into the dry clothes.

She slips on a pair of wool socks. “If you’re trying to keep hunters from discovering the Land of Milk and Honey, a waterfall would just about be the most effective lock and bolt. No hunter—assuming it could even survive the waterfall—would ever think to look back here. The Scientist is smart like that.” There’s a twinkle in her eye. “Try to keep up with me, okay?” she says with a smile.