The Forbidden Fortress Read online

  “Isn’t that nice,” said Mrs. Noland, sounding almost as toneless as her son.

  Not really. Howard was staring at the bat as if he’d never seen one before.

  The table fell silent. Mom cleared her throat and took a long drink of her lemonade. This was officially the most awkward birthday party I’d ever been to.

  “Open ours,” Savannah suggested. Howard grabbed our package and neatly unwrapped the paper.

  “Oh, a space pen,” said Howard.

  “Yeah,” said Eric, smiling. “We got it engraved.”

  “Thanks,” Howard said. He looked at his mom. “Look, you can use this, too. H. Noland can stand for Hope.”

  “That’s an awfully fancy pen,” Mrs. Noland said.

  “It was invented by NASA,” Savannah said. “It can write upside down, underwater . . .”

  “Wow,” said Mrs. Noland.

  “NASA spent several years developing this pen in the sixties, so the astronauts could write in zero g,” Howard said. “It’s been on every manned space mission since its invention.”

  Savannah and Eric beamed. “We knew you’d like it,” Savannah said.

  Howard looked at the pen. “But you know what the Russian cosmonauts did?”

  “What?” I asked.

  “They used a pencil.”

  Nate spit his lemonade across the table.

  “Nathaniel!” his mother said, horrified. “And Howard, that’s not how you thank people for gifts.”

  Mom was trying not to laugh.

  “I’m going to go get the food,” Nate said, his eyes watering.

  “I do like it,” Howard said. “There’s no such thing as a space pencil.”

  “You’re welcome, Howard,” I said. That was a thank-you, for him.

  Thankfully, Nate came back with a tray of food, and for a while the only thing we talked about was how to divide up the egg-roll calzones and whether sesame chicken pizza was better or worse than kung pao shrimp pizza.

  Mom poked at her chicken fried linguini. She really should have known better.

  “So, Dr. Seagret,” Mrs. Noland said, “Howard tells me you’re taking the kids to Idaho in the fall. We’ll be sorry to lose them. Howard has grown so close to Eric and Gillian.”

  Mom stole a glance at me, and maybe it was my imagination, but she almost looked guilty. Yeah, Mom. See? You aren’t just taking us away from Dad and my best friend, you’re also leaving Howard with no one but his brother and Savannah for company.

  And that was assuming Sav and Howard would still hang out once we were gone.

  “You tell her, Mrs. N,” Savannah said, twirling a fork through her Caprese chow mein. “Gillian’s only been here full-time for a year, and now she’s going to leave again? That sucks.”

  “Well, you’ll all just have to have as much fun as possible this weekend to make up for it,” Mom said. “They’ve got such lovely facilities at the Guidant campus. And it’s on the water, too, so you’ll be able to go swimming and water skiing and sailing. . . .” She gave Eric an encouraging smile.

  “Not a lot of sailing in Idaho,” I added.

  Eric kicked me under the table. “Who’s the silver one from?” he asked Howard, pointing at a rectangular present.

  “I don’t know,” Howard replied. “It showed up on the doorstep without a card. We think maybe it’s from my grandparents. It looks like a book.”

  “Why don’t you open it and see?” Nate asked. “By the way—spoiler alert—I also got you a book.”

  “Yeah,” Howard said. “But you got me that book on the effects of long-term space flight on the body . . . didn’t you?”

  Nate looked confused. “Wait, was that the one you mentioned five dozen times?”

  Howard looked at his brother. Nate waited three seconds before he grinned.

  “Oh,” said Howard. “You’re joking.”

  “Yeah.” Nate bit off a chunk of pizza crust. “Open the other one.”

  Howard pushed his plate aside and grabbed the silver gift. Inside was a large brown hardcover engraved with a simple gold title, Codes and Code Breaking. There was no author listed.

  “Cool,” said Howard.

  We all blinked at him. Cool? What did codes have to do with space travel? Coding, maybe, but I doubt a book that old had any cool computer stuff in it.

  “I taught myself Morse code this summer,” he said. “You’d think it’s obsolete, with the improvement in communication techniques, but I’ve been thinking a lot about the SETI Institute.”

  “SETI?” Savannah asked.

  “The search for extraterrestrial intelligence,” I explained. “They look for aliens.”

  “They study radio signals for signs of extraterrestrial communication,” Howard clarified. “But obviously, extraterrestrials aren’t going to communicate in English.”

  “They aren’t going to communicate in Morse code, either,” Eric said.

  “No,” said Howard. “Probably not. But the more I learn about how human languages and codes work, the more prepared I am.”

  “To talk to aliens?” asked Eric. He looked at me. “This is your doing, isn’t it?”

  I held up my hands in defense. I had nothing to do with Howard deciding that codes were as cool as the cosmos.

  “No, to separate signal from noise. Language has patterns. If you can figure out how the patterns work, you can figure out if it’s some kind of message. That’s the first thing you learn with code. Look . . .” He flipped the cover of the book open and tapped a page. “It’s called frequency analysis. You study the repetition of certain letters or groups of letters to try to break codes.”

  “Like how in English, E is the most common letter?” Savannah asked.

  “Right. And if there is a word with only one letter . . .”

  “It’s ‘I’ or ‘a,’” Eric finished. “Cool.”

  “So who gave you this book?” Mrs. Noland asked. “It’s not from us. And I know Grandma got you a sweater.”

  “Check in the front,” my mom suggested. “Maybe there’s an inscription.”

  Howard turned to the front of the book. Sketched out in pencil was a square of numbers.

  14 43 13 13 45 31 35 14 44

  25 11 53 15 43 23 35 11 34

  15 35 23 31 21 13 34 31 13

  52 13 45 25 31 44 53 31 34

  34 44 11 11 35 21 13 51 44

  13 24 51 34 45 11 54 11 51

  14 11 11 23 34 51 22 33 23

  43 15 34 11 54 44 31 51 44

  51 35 23 13 43 21 13 43 14

  “Weird,” Eric said. “Even the inscription is in code.”

  “Or someone was doing a math problem and needed paper,” Savannah said.

  But I was staring at the neatly drawn rows of numbers as my slices of sesame chicken pizza turned over and over in my stomach.

  Not again. How could they be looking at this writing—how could Howard be looking at it—and not see what I saw?

  If those numbers were a code, I had no idea what they meant. But I did know who’d put them there.

  Dr. Underberg.

  4

  SUB-SUB-SUBORBITAL

  I WAS IN A DAZE THROUGH THE REST OF THE MEAL, AS HOWARD OPENED his grandparents’ sweater and Nate’s book on long-term space travel and the new pair of sneakers from his mom. I barely touched my green tea ice cream sundae.

  Maybe I was just imagining it was his handwriting. Dr. Underberg wouldn’t send Howard a present. But my birthday wasn’t for a month yet, and he hadn’t sent Eric one on his. And how could he even send something from outer space, anyway?

  But if he had . . . why would it be a book on codes?

  After Mom drove us home from General Tso’s, Savannah headed back across the creek to finish packing for the trip, Mom went into her room to answer some emails, and as soon as we were alone, I cornered my brother near his room.

  “Hey,” I said. “Do you think Dad gave away all Dr. Underberg’s secrets in his book?”

  He shrugged. “I wouldn�
��t know. I never read it.”

  “You didn’t read Dad’s book?”

  “I lived it. Have the fake teeth to prove it and everything.” He tapped one of his ceramic incisors. “But yeah, I guess so. I mean, Omega City was his big secret, right? That and the battery.”

  “But it doesn’t say how to make the battery in the book.”

  “Well,” Eric said, “that’s because Dad’s not an engineer. I figured the battery is what the Guidant people are really interested in, don’t you?”

  I frowned. Fiona had wanted that battery. So had the Shepherds.

  Eric saw my face. “Come on, Gills. That’s not a bad thing, just because the bad guys wanted to steal credit for inventing the battery. Dr. Underberg would have wanted someone to use it. He was trying to save the world.”

  “‘Would have wanted’?” I echoed. “Do you think he’s dead?”

  Eric’s eyes widened. “I mean . . . I don’t know. He was really old and unhealthy and . . .” He frowned. “Why are you asking me about this? Howard is the one with the new book on the long-term effects of space travel.”

  I took a deep breath. “That’s not the only book Howard has. That code-breaking book—I think that was Dr. Underberg’s handwriting in the front.”

  Eric shook his head. “Oh, Gills, not the handwriting thing again.”

  “Again?” I said defensively. “I was right last time.”

  “He’s an old guy. They took penmanship classes and stuff back then, so they all had good handwriting. Maybe you just think it’s him because it’s an old book and it has fancy handwriting in it.”

  “What other old man would send Howard a book?”

  “From outer space? I have no idea,” Eric scoffed. “Besides, it’s not even real writing. Just a string of numbers.”

  “Hey, guys?” Mom’s voice floated down the hall. “Don’t stay up too late tonight, okay? We’ve got an early start tomorrow morning. Are you all packed?”

  “Yes,” we answered in unison.

  “Look,” Eric said. “What difference does it make if he is floating around up there, sending down birthday presents like a space-age Santa Claus?”

  “Well, if he is, then Dad doesn’t have the right to give away his battery without his permission. We have to find out.”

  Eric crossed his arms and gave me a smug glare. “We do, huh? When? Before tomorrow?”

  “Before we give Guidant the battery.”

  “We? A second ago it was Dad.”

  “Of course it’s we.” After all, I’d been the one to bring the battery out of Omega City in the pocket of my utility suit . . . even though it had been an accident. “That’s why we’re all going to Guidant.”

  “Um, no, it’s not. I don’t know the first thing about how patents or whatever work. But I’m sure Dad has thought this through, even if you haven’t.” Eric went on. “And here’s something else you haven’t thought through. If Dr. Underberg is out there, and Guidant or anyone else who might want to talk to him about his inventions could, what makes you think they’d want to talk to Dad . . . or us?”

  I clapped my mouth shut.

  Eric shook his head, like he was disappointed in me. “So which is it? Is Dr. Underberg out of the picture, or is he around to answer people’s questions while we’re with Mom in Idaho?”

  I clenched my jaw. “This has nothing to do with Mom . . . or Idaho!”

  “Sure it doesn’t.” He rolled his eyes and shut the door to his bedroom, leaving me to make faces at the wood.

  I TOSSED AND turned all night, my dreams a mishmash of thick sweaters, crashed rockets, and space pens. I couldn’t believe my brother. Sure, I didn’t want to move to Idaho. But not so much that I’d rather Dr. Underberg disappeared again . . . or worse.

  By the time I woke up, my brain was so foggy I could hardly think of what to pack. Eric and I still weren’t speaking to each other, and since I usually did my best not to talk to Mom, either, that meant I spent all of breakfast completely mute. By the time Savannah met us at the van to load up our bags, I felt as gloomy as the overcast sky.

  Savannah looked sunny, though—literally, as she wore a pretty yellow dress printed with daisies. And, I noticed, a bra.

  She frowned at my old jean shorts and T-shirt. “That’s not what you’re wearing when we have our meeting, is it?”

  “No. I’ll change when we get there.” Although now I wasn’t sure if the khaki pants I’d brought were the right choice, either. When Mom and I had gone shopping the other day, she’d bought me an A-line skirt she suggested I wear at Guidant, but I hadn’t packed it. Now I wondered if I should have.

  “I forgot something in my room,” I shouted, and ran back inside. The skirt was hanging in my closet and I grabbed it and stuffed it into my backpack, hoping that wherever we were staying on the Guidant campus had irons.

  “Don’t get too excited,” Eric was saying when I got back in the van. He was sitting shotgun. “I bet you a dollar Dad makes us all wear our utility suits when we get there.”

  “He wouldn’t!” Savannah looked at my mom. “Would he?”

  Mom chuckled. “He certainly didn’t mention anything like that.”

  “Then why did he make us bring them?” Eric teased.

  “For . . . props.” Savannah smoothed out her skirt. “Maybe it’ll be enough that Howard wears his.”

  I settled into the middle seat next to Savannah, but we didn’t talk much as Mom headed off to pick up the Noland boys. I wanted to tell Sav about my suspicions, but I knew the second I opened my mouth, Eric would start making fun of me again.

  Along with his bag, Nate carried an SAT prep book, and Howard—who was, of course, wearing his utility suit—came armed with Codes and Code Breaking.

  “Oh, are you studying for the SAT, Nate?” Mom asked, looking at him through the rearview mirror.

  “Yes, ma’am,” Nate replied. “I have to take it again. It’s the math that’s killing me.”

  “Have you thought of a tutor?”

  “It’s next on the list,” he mumbled. “If I can’t figure out rational and quadratic equations.”

  Beside me, Savannah twisted her hands in her lap. I’d bet a dollar she was as itchy to get her hands on Nate’s SAT prep book as I was to get another look inside Codes and Code Breaking. I had an idea.

  “Hey, Nate,” I said. “Can you switch with me?”

  Nate shrugged and we climbed over the backs of the seats. Last year, Savannah would have swooned to have Nate Noland sitting next to her. Now all she wanted to do was check out his calculations.

  Once I was buckled in next to Howard, I could see that he had his head bent low over the book. He had a small pad of paper nestled inside the pages, and it was covered in numbers and symbols I couldn’t begin to understand.

  “So it’s pretty good reading?” I asked.

  He grunted. The neck of his utility suit was zipped tight, and he was chewing on the zipper pull.

  “He was up all last night with it,” Nate announced from the middle row. “I think we may have discovered a new obsession.”

  “You forgot to divide by x,” Savannah murmured, mostly to herself.

  “What?” said Nate, then looked down at his work. “Oh, crud.” He started rubbing away his work with the eraser end of his pencil.

  I concentrated on Howard. “Can I see the book for a second?”

  He spat out the hexagonal zipper pull and said, “Maybe later,” which I’m pretty sure meant absolutely not. He turned another page, and I caught more telltale scribbles in Dr. Underberg’s handwriting. I arched my neck to get a closer peek, and Howard slammed his hand down over the writing.

  “Do you mind?” he asked. “If people watch me create my code, then it’s not very secret.”

  I sat back, frowning. “If you aren’t going to tell us your code, then who are you making it for?” I was no expert, but I was pretty sure the first lesson in any book on code making was that there was no point in writing coded messages if no
one else could break them.

  Howard said nothing, and after another minute of sitting in silence, I tried again.

  “Did you ever figure out who gave you the book?” I asked. “It’s so mysterious.”

  He stopped writing on the pad. “No, it’s not. It was the first code I broke. Turns out it was a simple Polybius square.”

  “Oh,” I said, like I’d heard of those before.

  “Chapter one.” He flipped to the front of the book. “They’re one of the simpler forms of ciphers. Well, easy as long as you can figure out what the keyword is. See, what you do is you make a square out of the alphabet, and then you number the axes, and every number combination conforms to a letter.” He showed me the diagram in the book.

  “Why do they put X and Z together like that?” I asked.

  “Because they’re rarely used,” he replied. “And because usually you will know in a word if it’s an X or a Z that you need. Anyway, if you’re writing out the code, you’d just use the corresponding horizontal and vertical axis letters to make the numbers. So A would be eleven, and B would be twelve, et cetera.”

  “Carry the twelve . . . oops,” said Nate from in front of us, starting in with his eraser again. “Guys, you’re confusing me with all this talk about axes and numbers.”

  “Yeah,” Savannah said under her breath. “That’s what’s confusing you.”

  Howard dropped his voice to a whisper. “This is a pretty easy code to break.”

  “It is?” I asked, looking skeptically at the lists of numbers. It didn’t look easy to me.

  “Well, it is if you know anything at all about codes. I mean, you shouldn’t use it in a war or anything, but it helps to make a quick code, or if your messages are extremely short. Also, if you wanted to make it harder to break, you can use a keyword.”

  “What do you mean?”

  It goes at the front of the key and kind of shifts the rest of the alphabet to the side. So say your keyword is ‘party’ . . .” He pointed to the next graph in the book, where that indeed was the keyword. “You just fill out the graph again, but you put ‘party’ on the first line, and then you skip all those letters when you get to them in the alphabet.”