I’d scarcely uttered the words before Kate was walking across the beach, away from the ship, away from the other passengers, toward the forest. I fell into step beside her as she strode through the palm trees.

“Where do you think you’re going?” I asked.

“We need to explore.”

“The captain doesn’t want us wandering off.”

“That’s not what he said.”

“That’s what it sounded like to me.”

“No. He said to make sure a crew member accompanied us if we ventured inland. Are you a member of the crew?”

“You know I am.”

“You’re accompanying me.”

“No, I’m not. I’m not coming.”

“Good-bye, then.”

We’d left the palms behind and were now in a bamboo grove, the yellow knobbly trunks as thick as my body, towering a hundred feet in the air. The white sand had given way to soil and ferns. Before us hung the dense green veil of the forest. Just looking at it made me feel all hemmed in.

“What about Miss Simpkins?” I cried.

“Her? She’ll sleep for hours. She excels at sleeping.”

Not much of a chaperone, our Miss Simpkins.

“Look, you can’t just wander off alone!”

“Are you going to stop me?”

“Yes.”

“How?” She stopped and looked at me, genuinely interested. “Would you grab me and drag me back?”

I blushed at the thought of it.

“Do you have handcuffs?” she wanted to know.

“Of course not!”

“You’d have quite a job if I struggled.”

“I suppose I would, yes.”

“Do you think you could flip me over your shoulder and carry me?” She puzzled over this for a moment. “I’m not sure you could manage it, if you don’t mind me saying so. Otherwise, you’d just have to drag me. Really, it seems hard to imagine you bringing me back unless I cooperated.”

I laughed despite myself. “I was hoping you’d listen to a bit of reason.”

“Reason,” she said. “How’s this for reason: this is the same island my grandfather saw. The creatures flew around this island. Remember, he saw that newborn fall into the trees. If it died, its bones should still be here somewhere. And surely there are others who died here. Bones, Matt, that’s what I’m after.”

“Fine, but we can’t just go wandering into the forest. It’s not safe.”

“It’s perfectly safe.” She kept walking.

“Miss de Vries, I must insist you come back.”

“I’ll be fine,” she called over her shoulder with a cheery wave. “Don’t you worry about me.”

I folded my arms across my chest and smiled. She would stop. When she realized I wasn’t about to rush after her, she would have second thoughts about pushing on into that forest alone. By this point she was getting quite far away and showed no signs of faltering. She pushed through some thick fronds, and I lost sight of her altogether.

I started counting. By ten she’d be peeping out from behind the foliage to see if I was coming.

By twenty she hadn’t reappeared.

“Bloody hell,” I muttered, running to catch up.

The foliage was so high and thick now I couldn’t see the sky. The humid air pressed against my chest. Great pinelike trees, with slender drooping branches, bristled with spiky flowers. Ferns and fronds and vines and brilliant petals were everywhere. A shrieking parrot flashed by, scarlet and green. Insects chattered in the perfumed heat. I kept looking for the light between trees, the brightness overhead, just wanting to punch through it all. Just wanting a horizon.

“Brilliant, you’ve decided to come,” said Kate with barely a backward glance as she kept walking.

“Miss de Vries—”

“You said you wouldn’t call me that anymore.”

“You haven’t traveled much, you said so yourself. But I’ve been all over.” I gave her a smile that I hoped she’d see as sophisticated and world-weary. “I’ve been all over the tropics and there’s things you’ve never even heard of. All kinds of wild animals—”

“I’ve read up on it, actually,” she said briskly, wacking away foliage with her furled parasol. “We shouldn’t run into anything too fearsome. Plenty of birds. Bats. Skinks. Lizards. Big toads. You won’t be seeing any big mammals, no tigers or lions or bears. Possibly a wild pig.”

“How can you know all this?” I demanded, keeping pace with her.

“How do you think? My grandfather flew over the Pacificus and I wanted to know all about the world he saw. I read up on Oceanica. Especially after I read his log. I’ve stared at pictures and memorized the names of the animals and trees and plants. What else was I supposed to do with myself?”

She looked at me defiantly, challenging me to contradict her.

“What about snakes?” I said, jabbing a finger at her. “Pythons!”

“Not indigenous.”

“Boa constrictor?”

“No.”

“Anaconda!”

“That’s South American. You won’t find any snakes here at all.”

She did have a way of stealing the wind right out of your sails. But I wasn’t quite finished with her yet.

“Just stop a second, will you? There may be people living on this island,” I said ominously. “And who says they’ll be happy to see us.”

She didn’t slow down. “Good point. But we mustn’t be governed by our fears, Matt Cruse. We have a duty, you and I.”

“A duty?”

“To science, absolutely. If there are bones on this island, we must find them.”

I sighed. I was still far from convinced these winged creatures even existed. But I could see she was hell-bent on looking for them, and I couldn’t very well leave her to go off by herself. Yes, Miss Simpkins, I saw her skipping off into the woods. No I didn’t go after her. Why would I? She seemed perfectly fine on her own. Wasn’t at all worried about her, no.

“It’s a big island, Kate.” I was starting to feel quite defeated. “You can’t explore it all. Where do you intend to start?”

“We just start,” she said. “Bones could be anywhere, if the creatures just fell from the sky. Of course, they might have been picked up by other animals. Unlikely, though—there’re probably no substantial mammals on the island.” A little furrow of concentration appeared over each eyebrow. “But all animals feed on carrion. So, around trees with bird nests, or the lairs of skinks and lizards.” She paused. “That’s fun to say. Skinks and lizards.”

The ground was rising now, and she was getting a bit puffed, with all the walking and talking. Heat sifted through the trees and fronds. My back was wet. My heart felt loose in my chest. I’d never heard such a ruckus of birds. They were chirping and warbling and hooting and tooting and screaming nonstop. You only had to look up to see a swoop of bright feathers and flashing tail plumage, and you couldn’t take many steps without getting pooped on by one of them. Cheeky things they were, and obviously not fearful of people, for they would sit and stare until we came quite close, crashing and slapping our way through the foliage. A truculent little budgie waited until I nearly trod on her before flitting away.

“You’ll get tired of holding that book,” I told her. She’d got it in a little purse with a braided strap that she had slung over her shoulder.

“It’s not heavy,” she said with a shrug.

I kept waiting for Kate to get worn out. Her dress looked like cotton, airy enough, but it went all the way down to her ankles, and she kept hiking it up with one hand so she could move more easily. She was bound to get hot and want to go back to the breezy shade of the beach. But she didn’t. I marveled at her stamina. When needed she scrambled over rocks and up little hills. She kept going.

I was not at all sure of the sense of this, but part of me was glad to be moving, relieved to be busy rather than lying still in my bunk, welded to the earth. Every few minutes I would turn round to take a sighting, so we’d be able to find our way back. It was hardly necessary, though. I was good with directions, as if I had a lodestone in my skull. You could spin me round and I could tell you the bearing without opening my eyes. I felt my compass, cool in my pocket.

Kate never looked back once. She was only interested in what was in front of her. Her eyes swept the ground, and she’d often stop and kneel to push back some ferns and peer about closer to the earth. Sometimes she’d look up into the tall, strange trees or just listen. She seemed to know what she was doing, but so far we hadn’t seen any bones, big or small.

It was midday now, and hotter than ever. The air was thick and heavy with scent. My temples streamed. I wished we’d brought water. But we hadn’t brought anything. We hadn’t planned. We were walking aimlessly through the tropical forest, in search of the bones of a creature that might not exist. I’d have to be back in a couple of hours. Not that Kate seemed at all aware of my duties and obligations.

“If I can collect a set of bones from this creature, imagine that!” she said. “Pictures, photographs would be excellent too, of course. But the Zoological Society might poo-poo them. Fakes, like the faeries, they’d say, like the Schlock Ness monster. Imagine the furor when I show them real bones. ‘How do you explain that?’ I’ll say to them.” She already saw it playing out in her mind like a cinema reel.

“I’m expected back soon,” I told her.

“Turn back any time you need to,” she said absently.

That was rich, I thought, feeling grumpier with every step. She’d taken no note of her path; she had absolutely no hope of getting back on her own. But maybe she knew that, just like she knew I would stay on with her and be her navigator. And she was right. I felt disgusted at my own powerlessness.

“You’re different here,” Kate told me. “On the ground, I mean.”

I said nothing.

“I think you’re more frightened down here than you were when the ship was about to crash.”

“You’re right,” I said. “I don’t like being on the ground. I don’t feel at home.”

“Do you think it’s because you were born in the air?” she asked. She looked at me as if I were a picture in a textbook.

I didn’t reply. I didn’t much like her calling me frightened.

“I can’t go back without you,” I told her impatiently. “You’ll get lost.”

“I’ll be fine.”

“Which way is it, then?”

She paused, frowning, as if this were all a terrible and needless annoyance.

“I’m not ready to go back yet.”

“But when you are.”

She sighed. “I know my way.”

“Just point.”

Her chin lifted and her nostrils narrowed. I tried to narrow mine too. I’m not sure it worked.

“That way,” she said.

I nearly hooted with delight. “Quite wrong. You’re off by forty degrees or more.”

“Forty degrees,” she muttered disdainfully. “I’ll just walk downhill. That’ll take me back to the coast.”

“There’s a lot of coast on an island.”

“I’ll just walk round.”

“Simpler if you knew where you were going.”

We looked at each other. I was waiting for her to ask me the right direction, but she didn’t.

“Listen,” she said. “Water.”

A little ways off was a sizable stream, half hidden beneath ferns. I reckoned it was the one that emptied out near the lagoon. We knelt down to drink. The water was clear and cold.

“Well, this makes things simple, doesn’t it?” Kate said jauntily. “We’ll just follow this upstream and, when we’re ready, let it lead us back down to the beach. See, now we know exactly how to get back.”

“I already knew.”

“Maybe you’d better go back to calling me Miss de Vries. I’m not accustomed to being spoken to so boldly.” For a moment I thought she was serious, but I caught the light dancing in her eyes. “You’re quite right. I’m hopeless with directions. I’m lucky you’re with me.”

I scratched my cheek, looking into the forest.

“I’m not frightened here,” I said. “Not exactly.”

“I didn’t mean you were scared. I just thought it was interesting you felt more at home in the sky than on the ground. With most people it’s the complete opposite. That’s all. It’s really quite fascinating.”

“I’m fascinating now, am I?” I said.

“Absolutely.”

“I just like to keep moving,” I said. “On land I feel like I’m going nowhere. I’m not good at standing still. I’m like a shark; if I don’t keep moving forward, I can’t breathe.”

“A shark,” she said, raising her eyebrow at me. “That’s quite a comparison. I wouldn’t say you’re really very sharklike, deep down. The dangerous, carnivorous man-eating Mr. Cruse!”

“I suppose not, no.” I blushed. “I just meant the moving part.”

We walked on and after half an hour seemed to have reached a bit of a plateau. More light was getting through the forest canopy. The birds really were tremendous here, and by now I was used to having them so close overhead, their quick shadows soaring over me, blinking out the sun.

Kate sighed and for the first time looked discouraged.

“Nothing,” she said.

“It’s a big island. It would take years to search it properly.”

“And we don’t have years.”

“There might be time for another look around.”

I couldn’t believe I’d gone and said that. It’s just that she looked so crestfallen and I wanted to cheer her up. But she was smiling at me now, and I had the uncomfortable feeling I’d just been juggled.

“Really?” she said. “You’d have another look around with me?”

“If there’s time,” I muttered. “Maybe. I can’t promise.”

“Thank you so much. I know you’ll try your best. Well, I suppose we should head back soon. I don’t want to get you into trouble.”

“I’m sure that’s uppermost in your mind,” I said.

Something slithered past my foot, and I stepped smartly out of the way.

“I thought you said there were no snakes here.”

It was curled innocently under a big fern frond. It seemed a harmless little thing, not more than a few inches, and a pretty bright red—a daft color for a snake among all that greenery. You couldn’t miss it. Any bird of prey would see it a mile off. A dainty little tongue lapped the air. This was no anaconda, no king cobra, no boa—I’d seen those snakes, and they were enough to make you run.

“Don’t move,” Kate said, her face pale.

“What?”

“I think that one’s poisonous.”

“This little thing?”

Then, in the unfriendliest way possible, it jumped. It launched itself sideways and arced through the air, straight at my face. Kate squealed, and I gave a shout, a not very polite one, and staggered backward. The snake landed not two feet from my shoes. Kate and I danced back some more, and that little red demon jumped again like it was half pogo-stick and scarcely needed to touch earth. I wouldn’t turn around to run, for fear it would land on my back without my knowing. So I ran backward, shooing Kate on ahead of me. The snake sprang again and this time lighted on the toe of my shoe. I gave a great footballer’s kick and sent it spinning through the air and into the distant undergrowth.

“It’s gone. It’s okay,” I panted, standing with my arms out, knees bent, watching. There was nothing to see, not so much as a ripple of leaves.

“Wasn’t he just the sweetest little thing?” I said, and started giggling.

“I’m sure he only wanted to say hello,” Kate added, giggling too. “I must remember to bring one back for Miss Simpkins.”

“There’re no snakes here, by the way,” I told her. “I’m completely sure of it.”

“Well, there shouldn’t be,” she said stubbornly.

“Then how’d you know that one was poisonous?”

“I’m pretty sure I saw it in a book,” Kate said, and then she screamed.

I whirled to see the snake springing up from the ferns and bouncing toward us, fast. This time we turned and ran. Kate hiked her skirt up high and held it bunched in one hand so she could take proper strides. Every time I looked around, the snake was still there. I wanted to laugh and scream at the same time. The little creature was ridiculous. It was terrifying, and it was also gaining on us.

“The tree!” Kate gasped, heading for an enormously thick tree with huge jutting branches.

“That safe?” I shouted.

“Think so.”

“Think so?”

“Snakes can’t climb.”

Which I didn’t think was at all true, but Kate was already at the tree and trying to get up the lowest branch. It was about five feet off the ground, and her boots skittered off the bark, and her skirts kept getting in the way. I looked over my shoulder and there was our little red friend sailing toward us and only needing two or three more leaps before we had a happy reunion. I grabbed Kate’s waist and heaved her up, giving her backside a push for good measure. One of her heels caught me in the cheek, but she was up, and then it was my turn.

“Make room!” I shouted. It was an easy jump for me. I was up in a trice and sliding my belly over the branch.

Below I could see the little red snake bounce straight up at my face, and I thought it was going to bite me on the nose. I recoiled, scrambling into a sitting position. The snake was a few inches short of the branch, and down it fell, but then it just bounced up again, and again, intent on reaching us. This snake was no quitter.

“Maybe one more,” I said to Kate, nodding at the next branch up. It was a great broad flat thing, sticking out horizontally from the trunk and mostly shrouded in a cascade of hanging vines from high above. There was an easy way up, for many stunted branches stuck out from the trunk, making a kind of spiral staircase.

“This way!” I stepped up the little branches toward the bigger one. I glanced down and couldn’t see the snake anymore. It had given up jumping.

“Never climb a tree in a long dress,” Kate panted, coming up behind me.

“I’ll remember that,” I said.

She had hiked her skirt up again, so high that I could see her gartered stockings. I tried not to look. She had knotted the skirt around her hip so she would not need to hold it.

We climbed. Crouched over, I pushed my head through the curtain of vines. Something hard knocked against my cheek, and I jerked back with a grunt.

“What?” I heard Kate shout behind me.

But I could not answer. I had stopped breathing. It was just inches away from my face. I could only gaze at the head that was staring at me from its eyeless sockets. Its fangs seemed enormous in its fleshless jaws. I forced breath into my lungs.

“It’s dead,” I said.

I made room for Kate on the broad branch, and cautiously she crawled through the vines.

“Oh, my goodness,” she breathed.

It was not just a skull but an entire skeleton, hunched down against the branch like something about to pounce. I wondered how long it had been here. Insects hummed and trilled and danced in the heat. Light slanted through the vines. The bones gleamed. Its claws were locked deep into the bark in its final death grip. Its flesh had been picked clean, but its bones were still miraculously attached, bound together by sun-cured sinew and leathery bits of muscle. It was easily seven feet from head to tail. It had died on this very branch. It had been here forever, just waiting to be discovered.

I looked at the long, flat skull, the fangs curving from the upper and lower jaws.

“It’s a panther,” I said to Kate.

“No…”

“Or some other kind of big cat—it’s got to be.”

“It’s not.”

“We should get out of here. There might be others around.”

“Look at it, Matt.”

I didn’t understand what I was seeing. The skeleton was all crumpled up along the branch, collapsed in on itself. I could make out the long, knobbly chain of vertebrae clear enough, and the rib cage, though some of the bones there were cracked or flattened. The legs I wasn’t too sure about, for they were folded at odd angles alongside the body, getting mixed up with the other bones.

“Its front legs…” I said, frowning.

They weren’t right. They were too long, especially the lower bones. They went on forever and ended not with a proper foot, but with a spray of whip-thin bones fanning out across the branch, trailing over the sides. I’d never seen anything like it.

“Those aren’t legs,” Kate said. “They’re wings.”

She was looking at me, her face flushed and shiny with sweat. Her breath came in little shaky pulses.

“How do you know?” I said. “How can you tell they’re wings? It’s just bones now.”

She scrambled closer to the skeleton. “Those are its fingers,” she said, pointing at the long thin bones. “They help support the wing. Have you ever seen a bat’s skeleton? It’s a bit like that. These are wings.”

I nodded, remembering the sketches in Benjamin Molloy’s journal. I’d seen giant flying foxes in the Dutch East Indies. They sometimes had wingspans of six feet, but their bodies were no bigger than a rat’s. This creature was much, much larger.

“This is no bat,” I said, swallowing.

“No.”

The exact same thought must have been bounding through both our heads, but I wasn’t ready to say it yet.

“But how could a creature this big fly?” I asked.

Kate leaned in close and gingerly picked up a large piece of fractured rib bone that had fallen on the branch. She smiled and handed it to me. My hand actually floated up as my fingers closed around it, for I’d been expecting something heavier. This bone was light as air. I held it balanced in my palm and could barely feel its weight.

Kate took it back.

“Look,” she said, holding the fractured end up for me to see. In the slanting light, I could see the bone wasn’t solid inside. It was a honeycomb of air and slivery struts.

“Like a bird’s,” she said. “To make them light. Imagine, if all his bones were hollow, he wouldn’t weigh much. And those wings. I’m trying to imagine them all stretched out. Four feet each, what do you think? An eight-foot span?”

“More. Nine or ten, I’d say.”

“Enough for flight?”

I nodded. “Enough sail to take him airborne.”

Her eyes widened. “And look here.” She was pointing around the creature’s rib cage. “Look at its breastbone. See, it’s got a kind of keel on it.”

“To hold the ribs together, to make them stronger,” I said. I knew what a ship’s keel was for.

“And to give the wings strength,” Kate added. “That’s where all the muscles would attach. Birds are the only creatures that have them.”

“How do you know all this?”

“Books,” she said.

I looked again at the skeleton. “So you’re saying this is some kind of big bird now?”

“Absolutely not. In a bird’s wing the metacarpals are all sort of fused together so it looks like just one digit. This creature clearly has five.”

I shook my head, not understanding.

“It doesn’t matter,” she said. “Just look at the skull. If it’s a bird, where’s its beak? Do you know any bird that has jaws or teeth like that?”

“Or a long tail,” I said, looking at the skinny line of vertebrae trailing on the branch. I needed to touch it again. I lifted the broken rib bone in my hand, felt its weightlessness. I felt weightless too, and hungry. I would drift right off the branch soon, up into the sky.

Since I’d last slept, pirates had boarded the Aurora and sunk her, we’d crash-landed on a desert island, and Kate and I had discovered the skeleton of some strange creature halfway up a tree. It had a bat’s wings, the hollow bones of a bird, the head of a panther. It was like nothing anyone had ever seen. I touched the dry hard bone of its skull. I didn’t know what it was, or what to call it.

“It’s one of them,” said Kate. “It’s just the way he described in his log. You can see that, can’t you?”

I remembered her grandfather’s careful sketches of skeletons. The human. The bat. And then the weird hybrid creature. It was just as he’d imagined.

“Yes,” I said.

“It’s real, isn’t it?” Kate said.

I nodded.

“They exist. They really exist.” She was staring at the skeleton. She was crying.

“What’s wrong?” I asked.

“He was right,” she said. “Grandpa.”

I nodded, surprised. Had she ever doubted him? She’d seemed so sure always. Or maybe it was just relief and excitement and exhaustion all swirled up together. It made me feel like crying too. Kate wiped her eyes, sniffed. I wanted to touch her but didn’t dare.

“It seems almost wrong to disturb it,” she said. “It’s so perfect. But I want the bones. I’ll need to take some photographs first. Just as it was when we found it. That way we’ll know how to put the bones back together. We could number them too.” She nodded, pleased with this idea. “Yes, we’ll number them. I’ve got a special wax pen that should work.”

“You do?”

“I do.”

It seemed she had no end of scientific gear with her. I marveled that it all fit on the ornithopter that brought her to the Aurora.

“You’ll be able to find this place again, won’t you?” she asked me.

I couldn’t help smiling. “Well, I haven’t really been paying attention to where—”

“Oh, don’t joke!” she said, grabbing my arm.

“Yes,” I said, “yes, I’ll be able to bring you back.”

She let go of my arm. I liked the way it felt when she’d squeezed.

“Bit of a slog carrying your camera and gear up, though. I suppose we could get someone to help.”

“No.”

She said it most emphatically, and I didn’t understand.

“We’ll tell no one.”

“What about the captain?”

She shook her head gravely.

I laughed. “We’ve got to tell the captain, at least!”

“Why? Is it ship’s business?”

“Well…”

“It has nothing at all to do with the ship or her well-being.”

“I suppose not, but why keep it secret?”

Her face had a hardness I’d not seen before. “If we go back and tell the captain, you know what will happen. He’ll forbid us from coming back to take pictures.”

“I don’t know about that.”

“Or at best he might send some of the crew to come and collect the bones, and then it’ll be taken from me. Put into the right hands, they’ll say. Let experts take care of these things.”

“The captain’s a fair man.”

“I’m sure he is. But you remember the letter they sent me, those important gentlemen from the Zoological Society. Turn your attention to more ladylike pursuits. They’d just take it away from me, and I won’t put up with it. This is our discovery, Matt. If we tell them, they’ll take it away from us. They’ll treat us like children.”

She had a point.

“Promise me you won’t tell.”

I said nothing for a moment, uncomfortable. I felt like she was making me choose between her and the captain, her and my ship. But maybe she was right: strictly speaking, this had nothing to do with the Aurora. It was something else entirely.

“So we’ll just come back to the ship with a big bag of bones. Look at all the mangoes we collected, everyone.”

“No one has to know what’s inside.”

“They might not be too keen to take on more cargo.”

“It’ll be light,” she said with a grin. “I’ll make room in one of my steamer trunks.”

“All right,” I said. “It’s a secret.”

“Our secret,” she said. “And when I get back home I’ll contact the Zoological Society. I’ll have photographs, the bones, the journal. They’ll have to believe me and my grandfather then.”

The Aurora was beached like a whale, but getting home was a certainty for her. She’d already leapfrogged time in her head, not just to her homecoming but to some glorious future. I wondered where I’d be then.

“I almost hate to leave it,” she said. “Afraid it won’t be here when we get back.”

“It’s not going anywhere.”

As I stared at the skeleton, I imagined muscles and sinews and tendons fusing with the bones, skin and fur growing over it all. I looked at the skull and pictured the jaws opening wide, a flash of life in the eye sockets. A bird shrieked, and I jerked.

“Come on,” I said, “we should be getting back now.”