In a detached way, Adelaide realized she’d misunderstood the geography. She’d been imagining a dome, but the actual shape made her think at first of a chocolate lava cake — a mound that caved in, and the part they were in now was exposed to the open air.

What that meant was that, when they’d thought they were seeing birds diving into tunnels, they were actually seeing them diving past the rim and into the caldera into which Adelaide and the rest of her companions were now staring. And those birds were still diving, and, now that she had a clearer look, Adelaide understood why.

All of the birds were carrying things in their claws — and they were claws, not talons, now that Adelaide looked more closely. In fact, each of the “birds” had a set of four wings, more like a dragonfly than anything avian, and a set of four claws like those on a crab. The things didn’t look like they could land, but what they could do was carry the silver orbs that the Strider’s crew had seen, collected, and dined upon. The bird-things would drop their payloads and then dive down into the pools in the valley.

But it wasn’t really a valley, and it wasn’t chocolate lava cake, because, once you saw its primary inhabitant, you couldn’t avoid realizing that the entire thing that they had once thought was an island was in fact a giant, floating nest. And in the center of it was a bigger bird than Adelaide had ever imagined.

Adelaide called it a bird because it had wings, feathers, and something like a beak, but the similarities mostly ended there. It had four massive wings and no legs that she could see. And the wings couldn't possibly lift it — it was the size of a schoolbus. Its head was only a massive beak that yawned open to lay almost flat, with no eyes that Adelaide could see. This maw was where the smaller birds were dropping the silver spheres, and the Mother was swallowing them without pause.

And it was clearly a Mother, because, even as Adelaide watched, it gave birth. An orifice opened on the side of the its body, between the wings, and four smaller creatures spilled out. There were no eggs, just a series of larval bird things covered in goo that immediately began to screech. The Mother barely seemed to register their having emerged, let alone their condition, so it was unclear what the screaming was for.

Until the Mother flapped her wings. Although they couldn’t move her, each wingbeat cleared the amniotic fluid away from the newborns and pushed them towards the pools the diving birds had landed in. The wind was powerful enough to cause Adelaide to tighten her grip on the edges of this nest, and she realized the source of the repetitive noise they had been hearing during their journey. The babies, meanwhile, began to flap their own little wings, pushing themselves along until they plunged into the pool full of a pinkish liquid.

“This is the grossest and most amazing thing I’ve ever seen,” Adelaide said, and then wished she’d taken a moment longer to find something with a bit more gravitas. Alessio was filming avidly, and she already wished posterity could forget the way she’d just put that.

“How much closer do we need to get?” Ray asked.

Adelaide looked at her wrist. “Just down to the edge of the flat part would be perfect. But, I mean, look at the size of that thing — you think we can make it without it getting mad at us?”

Jim looked down at the space before them. “There’s no way to know. But I don’t exactly see a security system. That giant thing is too big to move, I don’t see it chasing us. And isn’t there something where ants won’t attack you once you’re inside their hive? They might not even notice us.”

Hearing no objections, Adelaide began to slide very slowly down the incline. Her eyes were locked on the Mother, but it didn’t seem to notice anything. Adelaide supposed that shouldn’t have been surprising — it wasn’t clear if the giant creature even had sense organs. And it was making so much noise flapping its wings that Adelaide could barely hear her own footsteps. Still, she didn’t take her eyes off the massive beak.

Which was maybe a problem. If she’d been watching her steps, she might not have slipped on a bit of uneven surface. As it was, she failed to regain her balance, tumbled for about ten feet, and finally stopped , laying face down at the edge of the pool filled with that strange golden liquid.

The first thing she noticed was that the tracker on her wrist had binged — this was apparently close enough. That led her to her second thought — had she just broken the Deresonance Detector? She quickly pulled open her backpack and sighed in relief — everything looked ok. It was only then she had her third thought, which was, “I wonder if a giant bird monster is about to eat me.”

Before she could even look up, Ray was there, pulling her to her feet. Her tumble didn’t appear to have disturbed the natives, meaning that the effort spent on stealth had probably been wasted. Ray looked her over and asked, “Are you ok?”

“Yeah, fine. Embarrassed — do you think he caught that on film?”

“No comment.”

“Well, anyway, I got close enough — we can go now.”

Ray looked at the pool beside her and beckoned Jim down. “We will, but I want to take this stuff with us. I have no idea what it is, but it’s the kind of weird that can sometimes be profitable.”

The narrative has been illicitly obtained; should you discover it on Amazon, report the violation.

“You think people will want to buy weird juice that some giant bird bug things make?”

“People buy honey.”

Adelaide couldn’t argue with that, and soon Jim and Ray were filling their backpacks with what she now thought of as honey, although this was clearly less viscous. Adelaide saw now why Ray had insisted they spring for expensive backpacks for everyone. Having something watertight enough to use as a container for liquid was already proving invaluable. Unless the honey was worthless, but still.

It was Alessio, still by the edge of the tunnel, who first noticed it. He shouted, and everyone looked up.

It was hard to recognize by looking at any one bird-thing, but collectively, they were clearly growing agitated. Some of the birds in pools were taking flight, and some of those circling above waiting for an opportunity to drop their cargo were now descending in slow spirals, getting closer and closer to — well, to Adelaide.

“Ray —” she said.

“I see it. Run.” And Ray was already on the move, using his hands as he reached steeper terrain on the way to Alessio and the tunnel through which they had entered.

It was everything Adelaide could do to not look back, not look up and see if something was getting closer. There was no reason to check, she told herself, and it would only slow her down to look over her shoulder. She just looked at the ground in front of her and put one foot in front of the other, as fast as she could, and never looked back, just didn’t turn around.

Until she heard it.

It was so high-pitched, that was the horrible thing. Something massive like the Mother should have had a low-pitched roar, something that shook the ground beneath them. But this was just like a seagull plugged into an arena’s speaker system.

And suddenly she wasn’t looking forward or looking back, she wasn't looking at anything consciously, her limbs had taken over and she didn’t have a conscious thought until she was in the tunnel, running. Only then did she notice that nothing had followed them in and briefly wonder why, before she heard that horrible caw again and her body went back on autopilot.

When they reached the dinghy, Grant was looking anxiously at the sky, where flocks of bird-things were now doing rapid loops around the island. “You folks make someone mad?”

“Something like that,” Ray said. “Let’s go quickly — they don’t seem eager to pursue, but let’s not test them.”

But nothing followed, and Adelaide finally felt her heart stop racing. She looked back at what they had just left, and realized she still didn’t know what to call it - an island? A hive? A nest? She had no idea where it had come from, and she was thinking about it when she heard one last cry, distant but still unmistakable, and shuddered.

Ray put a hand on her shoulder. “It’s alright, Professor,” he whispered. “That was your first time seeing something like that, and now the worst is behind you. It’ll never be your first time again.”

***

Adelaide could finally think as the surface faded over the horizon and the Foam Strider was once again on uninterrupted ocean. The emptiness was a comfort — in the face of such vast expanses, it was hard to imagine that those cramped tunnels could even exist.

But they did, and Adelaide found she couldn’t stop trying to understand them.

Start with the surface itself. What was it? It didn’t seem to be rock — it was too warm, although it could have been heated by something. But there was a reason she had thought of it as a hive: it was porous and felt like an organic product. That would imply that it was made by the bird-things, but how? They didn’t seem to have anything that would let them make something on that scale. And how would they start? Bees started with pre-existing surfaces, but this was in the middle of the ocean. Was there a tiny island somewhere at the bottom that had been built out? Where had that horrible Mother been while the construction was happening?

The Mother was clarifying in some ways. It seemed clear, now, that the silver balls contained something that fertilized the Mother — Adelaide thought back to the afternoon spent picking seeds out of them and realized what she’d likely been touching. And what everyone had eaten.

But that made the silver balls make sense: they were designed to attract the attention of the drones, who probably selected the shiniest packages. But where and what were the fathers? What made those things, and why would they leave the nest/hive just to try to send their seed back to it? Or were they so dimorphic that the fathers couldn’t live in that habitat for long?

But the weirdest thing was: why were there tunnels? On the way in, they had seemed like giant versions of the tunnels in an ant colony. But the center here was open to the sky, and that was the way the drones made their deliveries. They had seen nothing that lived in the tunnels, and they weren’t needed to access the Mother, so what were they there for? And what had made them? None of the birds seemed to have the right equipment.

And the worst part was, no one would ever find out. They hadn’t brought a biologist, and they probably didn’t have time for one to solve this riddle even if they had. In a short time, they would sail back across the Triangle, and these creatures would vanish forever. There was an active debate about whether Seas vanished or simply became inaccessible, and normally Adelaide had very strong feelings about the physics implicated in that issue, but right now she just felt like she’d poked her head through the wardrobe into Narnia and then had the doors slam shut before she could walk through. Except Narnia was filled with horrible bird monsters, which maybe it was in one of the later books, she couldn’t remember.

She was watching the sun set over the horizon when Trish approached, standing next to her at the railing. “How was that today?” Trish asked.

Adelaide paused and took a deep breath. “It was interesting, and for a few moments I felt like a real adventurer. But, honestly, just between us, it was mostly just really, really scary.”

Trish wrinkled her nose. “I’m sorry about that. I’m glad you’re safe though! And, anyway, on to something new, right?”

Adelaide turned to look at the horizon towards which the Strider was sailing and found a smile coming to her face. “Yeah. Something new.”