What makes you ugly are the dark circles under your eyes,” Dmitri said to me the next morning as I zombie-shuffled out of my tent for some breakfast. I’d hardly slept at all, an hour at best.

“Thanks, Dmitri,” I said, noticing Crane dragging himself out of his tent. He also sported dark greenish-brown circles under his bloodshot eyes. Yet the campsite was humming with Hollis’s sape guitar, and I found him giving a recital of his new song to Diana and Dr. Reed by her hammock. I zombie-shuffled over.

“That was wonderful, Hollis,” Dr. Reed said, touching her chest. “Just wonderful.”

He pretended like he didn’t care and tuned his strings, but I knew he was thrilled.

“I didn’t realize you knew classical music so well,” Dr. Reed continued. “But being Yolanda’s son, it shouldn’t be surprising that you can play Brahms so beautifully.”

“Huh?” Hollis asked.

“Oh yes, what I remember most of our summer in Madagascar was listening to your mom practicing Brahms, his String Quartet in C Minor. The house was alive with that wonderful piece, even when she wasn’t playing! It was so soothing and beautiful, we’d all nod off. But you were just two or three and probably don’t remember that.”

Before Hollis could respond, Crane came bounding over, full of manic energy, telling everyone we had to get on the river in five minutes. Mr. Singh trailed after him. Apparently he’d developed a mysterious injury, because he was limping around on a crooked old cane. Had he injured himself on his midnight stroll into the jungle?

“Let’s get moving, gents,” Crane said, pointing specifically at Hollis and me. “Five minutes, everyone. Lim Sum, stop dawdling.”

We set off into the dark steaming water like a ghost ship armada, the sun behind us and shadows in front of us. We didn’t see another soul on the river all morning, just the steamy jungle surrounding us, getting thicker and denser with every turn. I could barely keep my eyes open. All morning, I drifted in and out of consciousness, riding the currents of Hollis’s gedang drum. After a lunch of sticky rice, we passed through some light rapids and then a hot drizzle. It was scorching out, the air as thick as syrup. So hot I could barely breathe.

In the trees, there were hundreds of little gray blurs darting around. It took me a second to finally recognize they were animals. Others were also sitting by the riverbanks, mamas holding babies, and smaller ones were playing or cracking rocks on little pellet-size fruit.

“Monkeys!” I screamed.

“Hey monkeys! Over here!” Hollis shouted, and took out his nose flute. “Maybe I can get their attention,” he said, and tried out a few different tunes. One of the little gray blurs glanced up briefly, then resumed rummaging around for brown pellet fruit. I heard Diana’s mini-operatic laugh from upriver.

“I didn’t know you spoke monkey,” I said.

“I don’t, but maybe that guy speaks nose flute.”

Even Tamon Dong, our driver, laughed at that. But the monkeys didn’t hold Hollis’s attention for long. Almost immediately, he was back to scratching at the red lump on his leg. “So, chief, your nose flute is impressive,” I said, trying to distract him. “And your drumming is insanely good. When are you going to combine them?”

“I don’t know,” he said, focused on his mosquito bite.

“’Cause I bet you could do it,” I said. “You’re an unbelievable musician. That thing you played last night —”

“Yeah, but I was just copying Brahms. Dr. Reed said so.”

“So what? You’re just a kid. You can write your masterpieces when you’re older.”

“Mozart wrote his first symphony when he was five.”

“Come on, Hollis, you write tons of music. All those songs you wrote last month for the Freight Elevators were amazing.”

“We’re called Secret Stairwell now, and those songs were just okay.” He paused for a long moment. “When we get back, I want to rededicate myself to music,” he declared.

“Rededicate? Hollis, you’re in like five bands.”

“But we’re just screwing around. It’s pretty simple music, actually.”

“It doesn’t sound simple to me. I’d give anything to play even half as well. You can play every instrument ever made.”

“But I want to really learn an instrument. When we get back, maybe I’ll call Arturo or Gabor from Mom’s old string quartet and see if they can teach me. Unless I’m too old already.”

“You’re eleven!”

“Those classical musicians can do stuff normal people can’t. And they never mess up, not once. They’re like super-heroes. It takes years to get that good. You think I could be that good, Leo?”

“Sure, chief, but classical music? Seems pretty boring.”

“It isn’t boring, Leo. Maybe I should be more like Mom. I wish I could just ask her what to do.”

Hollis puffed away some of the sweaty black hair that was hanging over his eyes and wiped his brow. He was pouring sweat, and his skin had a grayish pallor, except for that bump on his leg. That thing was red as an apple.

“Leo, I don’t feel good,” he said, rocking back and forth. “My stomach’s twitchy again.”

“We’ve just been on the river too long. Once you get on solid ground, you’ll —”

“But I feel all hot, too,” he said, suddenly shivering.

I waddled to the back of the boat and felt his forehead. “You don’t feel hot. And besides, you can’t get malaria. We’re taking the pills.”

“But that thing bit me before we took the pills. And what about all the water I was rubbing on it? Dmitri was telling me this morning about all the different parasites and bacteria in the water, and all the weird jungle diseases you can get. Some of them, Leo, nothing happens for years. But then one day you wake up and your eyes are all clouded over, and then you go blind.”

“Stop listening to Dmitri,” I said, wrapping one of our rain ponchos around him.

“Don’t touch me, Leo. You can’t make it better. I need Mom.”

I did, too. She could make it better; she could make anything better. No matter how sick you felt, she knew just exactly what you needed, just what food to make for you or how to touch you to make it all okay. I’m not saying she was a doctor or anything, but she could always make it better.

Clouds had moved overhead, and it started drizzling. When the drizzle turned to raindrops, we gathered all the boats together in the middle of the river. It was decided that the armada would pull in for the night just upriver, near the Pomantong Cave.

As soon as we were ashore, I took Hollis by the hand and raced him over to Dr. Reed, weaving between all the porters who were scrambling to set up the rain tarps and Crane’s deluxe tent.

“He’s got a slight fever,” she whispered to me, touching his forehead with the back of her hand. “Let’s get you somewhere out of the rain, sweetie,” she said to Hollis. “How about Crane’s tent?”

“Okay,” Hollis said meekly.

I was sick with worry. I was such an idiot to bring Hollis to this dangerous place. An idiot to take a chance with his life. All of my worst fears swarmed in my mind like a hornet’s nest, and the only thing I could do was walk. I just kept walking along the riverbank, away from everyone, until my heartbeat started slowing. Finally, I was able to tell myself that it would all be okay. It had to be.

I found a spot alone under some trees, overlooking the river. I sat down and stared into the clouds and mist, and listened to the raindrops plopping into the water, just trying to breathe. Eventually, the rain faded into a light drizzle, and together with the breeze rustling the leaves, it all sounded like someone saying shhhhh. But soothing, like a mom calming a toddler. The sun began to set, and the frogs began their chorus of croaks. For a moment, I found a little peace.

“There you are!”

I turned to see Diana trotting up to me. Her hair was wet and shining, but her green and yellow eyes were warm and soft.

“You’re so dark and mysterious, Leo. Going off by yourself to think deep thoughts in the rain,” she said.

“I’m just so worried about Hollis.”

“My mom thinks he just has a virus,” she said. “She knows a lot about this stuff. Come on. Let’s get your mind off this.”

“And do what?”

“Catch a frog, what else?”

I jogged after her as she skipped ahead of me, stopping at times to touch an orchid or to search for monkeys up in the jungle canopy. Occasionally, she’d turn around to see if I was still there and chuck a pebble at me. She laughed and teased me the whole time, and I began to feel a little more at ease. It was almost like we were still little kids back on that path to the pond in Madagascar, surrounded by plants and animals so colorful and astonishing they seemed out of a dream.

Sometimes Diana would get down really low and catlike, crouch close to the ground looking for a frog.

“Look!” she gasped, approaching a bizarre green and red spotted thing near the ground. “This is very special. Come here.”

It was a plant of some sort, at least ten inches tall, shaped like a cylinder with an opening at its top. It looked like a jug — except for the spikes running along its back. Inside it was filled with a reddish liquid.

“A Venus flytrap!” I said.

“Not quite. It eats bugs like a Venus flytrap, but it’s a pitcher plant. A Nepenthes. If we’re really lucky …”

She trailed off and picked up a long leaf from the ground, carefully lowering it into the mouth of the Nepenthes, her mouth open in concentration. Her eyes lit up. “Yes,” she whispered, and brought the leaf out, slowly raising it to her face. “Look, Leo. Come closer.”

I leaned over to her, almost cheek to cheek, so close I could feel the warmth of her skin. I looked down into the leaf, and there I saw a tiny shape, a green speck no bigger than a pencil tip. I looked even closer, and I saw an eye.

“You see it? It’s a tiny frog,” she whispered. “They spend their lives inside the pitcher plants — from eggs to tadpoles to full-grown, like this little guy.”

I put out my finger and hovered it over the frog, unsure of what to do.

“Here,” she said, and grabbed my hand, guiding my finger to the leaf. I let my finger slide down toward the tiny green speck with eyes. When it was within an inch or so, the little guy jumped, seemed to disappear for a moment, then I saw it just below my fingernail.

It croaked.

“It’s beautiful,” I said, feeling my heart beat fast after I said it. She smiled at me, a full fantastic smile, and when she looked at me, I felt myself drift dreamily into her eyes.

We put the tiny frog back, watched him settle down into the safety of the Nepenthes flower, and felt the warmth of the sun breaking through the clouds. I felt like I could stay in that spot forever, but I knew I couldn’t.

“We better get back to camp,” I said after a while, and she nodded.

Hollis was lying in bed in our tent, with Dr. Reed watching him. She explained that he might be reacting to the malaria tablets, or have a minor flu bug. Diana gave him wildflowers, and I offered to stay with him so the girls could get ready for dinner.

“Hey, buddy,” I said to Hollis after they’d left. “They say you’re A-OK.”

He stared at me with his dead animal eyes, all wrapped in blankets. “I feel hot.”

“Keep the covers off if you’re hot.”

“Then the mosquitoes will bite me.”

I knew what he was feeling. When you get stuck in a worry mode, everything seems bleak. To distract him, I told him about the tiny frog Diana and I had seen. Just describing it made me smile. But not Hollis.

At dinnertime, I brought him some sticky rice and river fish, but he didn’t touch it.

“Try to sleep,” I said to him, but his eyes remained open. I thought about singing him Brahms’s Lullaby, but I can’t sing a lick. Poor Hollis, he just tossed and turned and scratched at his bite. It took hours, but eventually he fell asleep, and I guess, so did I.

I woke up on my own just before sunrise, yawned, and rolled over to check on him.

“Hey, chief,” I whispered. “You feeling better?”

But there was nothing in his bed except a pile of sheets. My brother was gone.