Imagine if you found someone’s diary—someone you’d read about your entire life. Let’s say, for example, Santa Claus. What a find that would be. Dear Diary, Today I told Mrs. Claus that I was sick and tired of being a glorified delivery boy and that I wanted to go back to college and become a taxidermist. It’s always been my dream to be a taxidermist. Or how about the Tooth Fairy? Dear Diary, I’m so totally in love with the boy next door, but every time I see him, I’m always carrying a big, stinky tooth, and I think he thinks I’m weird. What should I do?

To Homer and Lorelei, Rumpold Smeller the Pirate was as much a character from a storybook as he was a real person. He’d lived on this planet—no doubt about that. But his adventures were woven from the threads of historical fact, hearsay, and exaggeration, forming a tapestry of legendary proportions. What was true, what was fiction, no one really knew.

Until now.

Homer sat on the submarine’s floor, crisscrossed his legs, and held the diary in his lap. Hercules and Lorelei sat on either side, pressing their shoulders against Homer’s. Dog pushed beneath the diary and draped himself over Homer’s lap. He’d found the treasure, after all, so he had every right to the best seat in the house. Homer cleared his throat and turned to the next page. Then he read out loud.

Dear Diary,

Today, on the eve of my thirtieth year, I begin this diary. It may seem odd that I waited so long to write about my life, but until this moment, I’ve been much too busy to put quill to parchment. You will discover how busy I’ve been as you read about my adventures traveling the world and collecting treasure—from the forbidden palace in China, where the emperor himself gave me a yellow ball of dragon’s saliva to—

“Hey, that’s part of the riddle,” Hercules said.

“Shhhh,” Lorelei shushed. “Keep reading.”

—to the piranha-infested Amazon, where a chieftain gave me the key to a lost city.

But how is it, you must wonder, that I now find the time to write? As I look out my porthole, a British naval ship, the HMS Bombastic, sails on the horizon in fast pursuit. Captain Ignatius Conrad appears determined to capture me. I fear my life will be coming to an end sooner than I’d like.

So in the time I have left, I will tell you my true story as I lived it. But be warned, I will not reveal the location of my treasure in this diary. What I will do, however, is to clear up some of the rumors about me. As you shall read, I’m not the cold-blooded killer the world thinks me to be. As you shall also read, I’m not the person most people think me to be.

I am known as Rumpold Smeller the Pirate, but I was not born with that name. I was born Rumpoldena Smeller, the only daughter of Duke Smeller of Estonia.

Homer stopped reading. “Wait a minute. That can’t be right.” He read it again.

I was born Rumpoldena Smeller, the only daughter of Duke Smeller of Estonia.

Lorelei grabbed the diary from Homer’s hands. “He’s a girl? I mean, she’s a girl? Wow, listen to this.” Lorelei read the next sentence.

In order to live the life I wanted, I cut my hair short, wore the costume of a boy, and took my brother’s name.

“She’s a girl. A girl!” Lorelei beamed.

“That’s amazing,” Hercules said. “She looks like a boy in all the drawings.”

Homer’s thoughts traveled through the pages of his books back home. Every drawing of Rumpold showed him as a man with pants and a sword and a Jolly Roger flag. Sometimes a severed head dangled from his hand, and sometimes the bodies of his victims lay at his feet.

“Wait a minute,” Homer said. “All those drawings were based on his legend. Rumpold himself only posed for three portraits, and he doesn’t have a beard in any of them. I bet if we looked at those portraits, now that we know the truth, we’d be able to see that he was actually a girl.”

“This is huge,” Lorelei said. “This is going to change history.”

Never ever would Homer have guessed this secret. Because he’d kept a number of secrets, he knew how often they tried to free themselves. How tempting it was to tell someone, just so the secret would stop tickling for a bit. What a feat Rumpold had accomplished. She’d pretended to be a boy for most of her life. It was a secret worthy of some sort of award.

Mr. Bernard Dullard would be in shock when he learned the news. As the author of The Biography of Rumpold Smeller, he would have to rewrite the entire book and change all the hes to shes, and that would certainly take a very long time.

“Now that I think about it, it makes total sense that the most successful treasure hunter in the world was a girl,” Lorelei said.

“What is that supposed to mean?” Homer asked.

“Girls are better at finding things,” was her explanation.

“You mean girls are better at taking things,” Homer said with a frown. “And they’re better at lying.”

“That’s not true.” Lorelei was about to whack Homer with the diary when Hercules, who’d been oddly quiet, cleared his throat.

“I think you’ve both been lying,” he said. Homer and Lorelei shared a fleeting glance, then fell silent. “I’m part of this quest, and you’ve been keeping a secret from me.”

“What do you mean?” Lorelei asked innocently.

Hercules pushed up the sleeves of his rugby shirt and leaned his elbows on his knees. “There had to be a reason why Lorelei kept kidnapping Dog. There had to be a reason why she wanted Dog to be a part of this quest. He can’t smell, but he was sniffing Captain Conrad’s chest. And he was sniffing the treasure map back at the lair. I’m not stupid. I know there’s something going on.” A hurt expression washed over Hercules’s face. “Don’t you trust me enough to tell me the truth?”

Homer felt about as small as an ant. And his heart grew heavy as he looked into Hercules’s sad brown eyes. Hercules had been true and loyal. Without his help, the quest to Mushroom Island would have been a failure. Without his bravery, Dog would have fallen from that airplane and been squashed. It was the biggest secret Homer held, but it felt wrong to keep it from Hercules. “Dog can smell treasure,” Homer said.

Lorelei smacked Homer’s arm. “What are you doing?”

“I should have told him,” Homer said. “He’s my friend, and he’s risking his life on this quest.”

“But—”

“But what?” Homer said sharply. “I trust Hercules a million times more than I trust you, Lorelei. Dog’s my dog—don’t forget that. I get to choose who I tell.” Lorelei grumbled something under her breath, but Homer didn’t care about her opinion at that moment. He cared only that he’d hurt his friend’s feelings. “I’m sorry I didn’t tell you,” he said to Hercules. “My uncle Drake knew that Dog could smell treasure. That’s why he kept Dog, and that’s why he made sure I inherited Dog. And Lord Mockingbird knew because he once owned Dog. But now only the three of us know.”

Hercules reached out and patted Dog’s rump. “If word got out, Dog would be in danger.”

“That’s right,” Homer said. Then he leaned close to Hercules and whispered, “I’m glad I told you. If anything happens to me, someone other than Lorelei should know. Someone who will protect Dog.” Hercules nodded.

“I don’t care if you’re whispering about me,” Lorelei said huffily. “I’m going to read Rumpold’s diary because it’s a million times more interesting than anything you two have to say.”

A buzzer sounded. Homer scrambled to his feet and rushed to the console. The speedometer moved from HYPER to SLOW. A button labeled ICEBERG AVOIDANCE SYSTEM lit up.

“Look,” Lorelei said, pointing. The headlight beams grazed across a large glistening shape.

“Iceberg!” Homer cried. He grabbed the steering wheel, but the submarine didn’t respond. “We’re on autopilot,” he realized. “I can’t do anything while we’re on autopilot.”

“Uh-oh.” Hercules threw himself into a seat and latched the belt.

Unfortunately, a seat belt would offer little protection. The Worst Ways to End a Treasure Hunt had an entire chapter dedicated to iceberg disasters. Upon contact, merchant schooners were reduced to fireplace kindle, pirate ships were gutted like dead fish, and ocean liners plunged to the bottom of the sea. Icebergs were a seafarer’s foremost enemy. The little submarine stood no chance if it crashed into such an imposing foe. Homer pushed the ICEBERG AVOIDANCE SYSTEM button.

“Hang on!” Homer cried as he jumped from the seat and threw himself over Dog. Dog, who’d been chewing on an energy-bar wrapper, moaned. Homer squeezed his eyes shut, waiting for the impact, but nothing happened. The submarine took a gentle turn to the right, avoiding the ice chunk.

“That was close,” Lorelei said, wiping sweat from her forehead.

“Uh-oh,” Hercules said, pointing as another chunk of ice appeared. The Iceberg Avoidance System continued to operate, and the sub turned just in time.

And that is how the next hour passed. Ice chunk after ice chunk loomed, and the submarine maneuvered around and between the chunks like a confident sea lion. The kids sat in the seats, their gazes glued to the awesome sight. It was as if they’d entered another world. Each chunk contained its own magic. Each chunk contained its own story. Dog sat on Homer’s lap, mesmerized by the sparkling landscape of blue and white.

“I’ve never seen anything so beautiful,” Lorelei whispered.

Schools of silver fish passed by, darting between icy crevasses. Dog barked as a larger fish appeared at a corner of the windshield.

“Oh, look,” Hercules said. “It’s a narwhal.” The whale was sleek and dark against the ice, like a torpedo. It turned its head for a moment, staring at the submarine’s occupants, then swam out of view, its tusk leading the way.

“Wow,” Homer said.

“Double wow,” Lorelei said.

Hercules, who could have told them that the word narwhal comes from the Old Norse language, simply took a deep breath and said, “Triple wow.”

The speedometer’s dial moved from SLOW to DRIFT. The coordinates flashed on the autopilot screen, followed by DESTINATION REACHED.

“We’re here,” Homer said. He could barely believe it. “We’ve reached Greenland.”

Lorelei pressed her palms on the window. “The treasure’s out there.” As she said that, a shiver ran up Homer’s spine.

They resealed the diary in its waterproof skins and set it into the chest for safekeeping. If all went well, there’d be plenty of time to read about Rumpold’s adventures. If all didn’t go well…

Homer didn’t want to think about that.

The submarine surfaced, and the battery shut off. Homer climbed the conning tower and opened the hatch. Cold air rushed in, and it felt as if ice water had been poured over their faces.

“Brrr!” Lorelei complained. She wrapped her arms around herself. Homer’s jaw tensed against the frigid temperature as he stepped to the top rung and stuck his head out of the hatch.

They were adrift in a small inlet. According to Homer’s Quality Solar-Powered Subatomic Watch, it was 10:00 p.m. Wednesday. Gulls cried overhead, circling the strange contraption that had invaded their quiet world. Jagged, snow-covered mountains loomed, sheer walls of gray standing in silent greeting. Chunks of ice clung together at the water’s surface as if a giant had dropped his snow cone. “It’s freezing out there,” Homer reported as he closed the hatch and climbed down. He couldn’t feel his nose or cheeks.

“Your lips are purple,” Hercules pointed out. “We need warmer clothes.” While he shuffled around in the supply locker, Homer turned the engine back on.

“We’ll need to find a place to moor the submarine. I saw a rocky ledge I think we can tie up to.”

Hercules found some parkas that were lined with white fur. And he found fur-lined boots and gloves. They were a bit big, but they’d have to do.

“What about Dog?” Homer asked.

“He’s already fur-lined,” Lorelei pointed out as she pulled on a pair of boots.

“Yeah, but his paws aren’t fur-lined.”

“Oh, good point.”

Dog would certainly be more comfortable waiting inside the submarine, but since he was the only treasure-sniffer in the group, he was needed on the surface. So, using Homer’s Swiss army knife, Lorelei cut some fur-lining from her parka and secured it around Dog’s paws with the laces from her sneakers.

“That’s quite clever,” Hercules said.

“You have to be clever to survive in The City on your own,” she told him.

Homer drove the sub close to the ledge. After shutting off the engine, he and Lorelei climbed out and onto the water-drenched deck. Even with the layer of fur, the cold soaked through to their skin. Homer stepped onto the rocky ledge and Lorelei tossed the mooring line. He pulled the sub close and tied the line around a boulder.

“Okay!” he hollered. “You can bring Dog.” Then the members of L.O.S.T. and FOUND walked along the ledge until they reached the beach.

The beach on this southernmost tip of Greenland was nothing like the beaches back home, which were made of fine gray sand, clamshells, and the occasional hopping sand flea. Saucer-sized rocks covered this beach, making it difficult to traverse. The rocks rolled underfoot, creating ankle-twisting wedges.

“The air is so dry,” Hercules said. “My sinuses are closing up. And my throat is getting sore. I wish I had a lozenge.”

“My watch says it’s forty-five degrees Fahrenheit,” Homer said. “I thought it would be colder than this.”

“It feels colder,” Lorelei said. “That wind is going to freeze my brain.” She pulled her hood tighter.

The wind did carry a sharp bite. It jabbed its way up Homer’s nose, so he pulled the parka’s collar as high as it would go. He worried about Dog, but Dog showed no signs of shivering. He wagged his tail, seemingly happy to be on land.

Just beyond the beach, the ground was interwoven with patches of thick-bladed grass, grayish moss, and piles of rocks. White-petaled flowers peeked from between the rocks, their yellow faces turned toward the horizon. Lorelei stopped walking and stared at the sky. “The stars aren’t very bright.”

“It’s not going to get any darker,” Homer said. “It’s summer, and we’re close to the Arctic Circle. Up here, the sun rises almost as soon as it sets.”

Lorelei pulled Rumpold’s map from under her parka and unfolded it. “The Draco constellation winds around the Little Dipper,” she said, and they all peered up at the sky. Homer had seen the Little Dipper many times in his own backyard, so it was easy for him to find.

“I see Draco,” he said. “There’s the tail over there. The nose is over there.” His legs began to tremble, but it wasn’t on account of the icy wind. “Rumpold Smeller stood here,” Homer said. “He looked at these same stars.”

“She looked at these same stars,” Lorelei corrected.

“Do you think we should start calling her by her real name?” Hercules asked. “Rumpoldena?”

“No way,” Homer said. “I say we keep calling her Rumpold. She claimed that name, and that’s how everyone knows her.”

“I agree,” Lorelei said. “Lots of girls have names that used to belong to boys. It’s no big deal. A person can change her name if she wants. I might change my name one day.”

“What would you change it to?” Hercules asked.

“Something heroic,” she said. “Something brave and strong—like your name.”

Hercules paused thoughtfully, then said, “A butterfly would still fly without the butter.”

“What’s that supposed to mean?” Lorelei asked.

“It means your name doesn’t define you,” he replied. “It’s what you do that defines you.”

Yeah, like dognapping and double-crossing and stealing, Homer thought. But he didn’t say those things to Lorelei. The moment was too exciting to be ruined by another argument.

The fur on Homer’s hood rippled as he returned his focus to the map. “So,” he said, putting his best reasoning skills into action. “Rumpold stood here, looking up at this sky, and wrote the riddle. ‘Twins of flame above and below.’ We see our dragon above, but where is our dragon below?”

“We should walk around and see if anything looks like a dragon,” Hercules said.

“And see if Dog smells anything,” Lorelei added.

So they walked as far as they could, to the cliffs, then back to the beach. The inlet was small and horseshoe-shaped. Other than scaling the mountains, there was nowhere else to go. Dog ate some tufts of grass and clumps of moss, but he didn’t sniff at anything.

“What about that rock?” Hercules asked. “Do you think that looks like a dragon?”

“It looks like a rock,” Lorelei said grumpily.

“Yeah, I guess you’re right.”

Homer held the map up to the sky and recited the riddle. “ ‘Twins of flame above and below.’ Above and below.” He looked at the sky. He looked at his feet. “ ‘An endless mirror between.’ ” He slowly lowered the map and looked at the water. The water in the inlet was calm, the stars reflecting like…

“The mirror is the sea,” he called.

“Oh, that’s brilliant!” Lorelei rushed to his side. “ ‘An endless mirror between.’ If the mirror is the sea, then the other dragon must be below the water. You know what that means?”

Hercules groaned. “It means we’re about to go swimming?”

Homer smiled. “It means we’re about to find sunken treasure.”

But before this realization had settled over them, a rumbling sounded in the distance. Dog dropped a moss clump and turned his face toward the sound. It was an engine of some sort, approaching from the south.

Seabirds fled their cliff-face nests as a seaplane buzzed over the inlet, sending ripples across the water. Homer, Lorelei, and Hercules ducked as it skimmed over their heads.

Homer reached down and grabbed Dog’s collar. Something was terribly wrong. The seaplane took a sharp turn and headed back toward the beach. Homer couldn’t run, couldn’t breathe, couldn’t think clearly, as fear filled his entire body from head to feet.

For as the plane approached, the pilot’s face, which was a mere speck behind the windshield, became clearer and clearer, closer and closer, until the wicked smile of Madame la Directeur was in perfect focus.