The Shadow Cipher

  “Who are you?”

  “I’m Tess Biedermann, Mr. Perlmutter,” Tess said. “And this is Theo and Jaime. We live upstairs?”

  “Well, do you or don’t you?”

  “Pardon?”

  “Live upstairs?”

  “Yes. I live upstairs. Theo and I live with my parents. The Biedermanns. My mom’s a cop?”

  The rheumy eye blinked. “Well, is she or isn’t she?”

  “What?”

  “A cop.”

  “Yes. Yes, she’s a detective.”

  “Then stop asking if she is. What do you want?”

  “I was wondering if I could borrow an egg because I’m baking—”

  “An egg? Do you think I can digest eggs with my stomach? What do I look like, a snake?”

  This was going about as well as Jaime had expected, which was not well at all. “Sugar?” he suggested.

  The rheumy eye rolled up to Jaime. “What are you, a comedian? I’m ninety-two years old. I can’t eat sugar. You want me to get the diabetes?”

  Tess gritted her teeth. “No, of course not. We’d love for you to stay around for another ninety-two years.”

  “Ha! Listen to you! Attitude all over! You kids! You think I’ve never heard a smart mouth before? I was born with a smart mouth!”

  “No kidding,” Theo said.

  “Is that a question?”

  “No.”

  “Are you going to tell me what you really want or are you going to keep on with the smart mouth?’

  “Oh, I thought I’d keep on with the smart mouth,” Tess said.

  “Ha,” he said. “Go on home to your mother. Maybe she’ll arrest you and let the rest of us find some peace.” The door started to close.

  Jaime slapped a palm to the surface and said what they should have said in the first place, the truth: “We need to look at your bedroom wall. Under the window. We need to see if there’s a seal there, and we need to take it with us. It might help to solve the Old York Cipher. Or part of it. Maybe.”

  The eye blinked some more. It blinked so long that Jaime thought Mr. Perlmutter had fallen asleep blinking. Then, gnarled fingers fumbled with the chain and the door opened.

  “Fair enough. Come in, if you must.”

  Mr. Perlmutter was stooped over a walker, three hairs combed over his freckled head. He backed up and did a wide turn into the apartment. Tess followed him inside, Theo and Jaime behind her.

  “Oh, look. A crowd of teenagers. It’s my lucky day,” said Mr. Perlmutter.

  “Thank you for letting us in, Mr. Perlmutter,” said Jaime.

  “Yeah, yeah,” he said. “Do what you have to do. But don’t touch anything! I got everything where I want it! Only took me seven decades.”

  Jaime ducked into the back bedroom. Another three seals in the middle of the top of the molding. He pried them off, spackled it smooth.

  “Thanks again,” Tess said when he got back to the living room. “We’ll get out of your way.”

  Mr. Perlmutter maneuvered himself toward a well-worn armchair the color of yams. He carefully lowered himself into it. “Whatever you’re doing, you might want to do it faster. Some of us aren’t getting any younger.”

  “Okay, Mr. Perlmutter.”

  As they walked out the door and into the hallway, Jaime thought he heard Mr. Perlmutter say, “And some of us have nowhere else to go.”

  CHAPTER NINETEEN

  Tess

  As quietly as they could, they crept into Jaime’s apartment to find Jaime’s grandmother standing in the kitchen, pointing a knife at the three of them. “Have you brought me my key ring and toolbox, you bad, bad children?”

  Jaime stopped short just inside the doorway, and Theo slammed into his back. Tess maneuvered around them both.

  “Is that dough for pastelitos, Mrs. Cruz?”

  Mima made a sharp cut in a sheet of pastry on the table in front of her. “Yes,” she said, “guava and cream cheese. My mother’s recipe. Not that you will have any, because children who steal people’s keys do not deserve any pastelitos.”

  “Mima,” Jaime began.

  “James Eduardo,” Jaime’s grandmother said, “did you think I wouldn’t hear you swipe the keys from the counter?”

  Jaime frowned. “I was quiet!”

  “Yes! Like a polar bear is quiet! Or maybe a dinosaur on a Starrboard is quiet!” Mima made another sharp slice in the pastry and then aimed the knife at the kitchen counter. “Keys. Box.”

  Jaime pulled the ring from under his shirt and laid it and the box on the counter.

  She jabbed with the knife. “Talk.”

  “If we talk, can we have some pastelitos?”

  “Bad, bad children are not in a position to make bargains, but I will think about it.”

  Jaime pulled out his sketchbook and showed her the grids, explained what they were looking for. “There are seals just around the windows in certain apartments.”

  “Yes, yes. I know. You could have asked me. I am not so scary. Well, maybe I am. Anyway, why not check the other apartments on all the floors?”

  Jaime looked at Theo and Tess. They’d told Mr. Perlmutter the truth. Why not Mrs. Cruz? Didn’t seem like they had anything to lose, not at this point. They didn’t tell her the whole story though, the entire new line of clues. All they said was that the seals near the windows could mean something.

  “Mean what?”

  “It’s a cipher,” said Jaime, opening his sketchbook. “One that I’ve seen before.” He handed the book to Tess. “What does this look like to you?” On the page, Jaime had sketched what looked like a tic-tac-toe grid with dots.

  “It looks like that cipher they had at the archives!” Tess said. “A Rosicrucian cipher?”

  “That’s why I remembered it,” said Jaime.

  “Rosi-what?” said Mima.

  “A type of secret writing used by some secret guilds or clubs. Freemasons, guilds like that,” said Theo.

  “Silly men and their silly secret clubs. Who needs a club to feel important? Ben Franklin needed a club? George Washington needed a club?” She rolled her eyes.

  Jaime said, “You belong to a bowling league.”

  Mrs. Cruz’s dark eyes narrowed, and she sliced another triangle into the sheet of dough. “Did you check all the other apartments for the seals?”

  “Are there more seals?” Theo asked.

  “No,” said Mrs. Cruz. She wiped her chin with the back of her hand, leaving a stripe of flour. “I would still check the other apartments.”

  “Why?” said Jaime.

  "Because I would like you to get caught by one of the tenants and have to explain this kooky stuff to them.”

  Jaime said, “It’s not kooky.”

  His grandmother put down the knife. “The whole thing is kooky. Who leaves the fate of so many people in a puzzle none of the people can solve?”

  “Good question,” said Theo.

  “We’re going to do it,” said Tess, lifting her chin. “And the Morningstarrs didn’t make a puzzle no one can solve—they made a puzzle only the right people can solve.”

  Jaime’s grandmother’s sharp eyes took Tess in. “You can have some pastelitos, but only if you help to fill them.”

  They spooned the guava-and-cream-cheese filling onto the triangles of pastry and then sealed the pastry into little pockets and placed them on cookie sheets. After the sheets went into the oven, they sat in the living room and went over their chart. Jaime paged through his sketchbook and found the key he’d seen at the archives:

  “Hmmm,” said Theo. “This isn’t quite the same, though. According to this key, the lines in the grid are important. They help form the cipher text. See?” He pointed to Jaime’s name, which Edgar had enciphered using the key, and which Jaime had scribbled in his book.

  “But here in this building,” Theo continued, “the seals—or dots—are all technically inside individual squares. So how would this work? A number of letters would look the same.”

&n
bsp; “Maybe they wanted to make the puzzle harder,” Jaime said.

  Tess said, “Or the lines aren’t important,”

  At the same time, Jaime and Theo said, “They’re important.”

  Tess’s eyebrows flew up like window shades.

  “But maybe not important in this puzzle,” Jaime said. “What if we only need to read the position of the dots?”

  They compared the locations of the seals to the locations of the dots on the key. Jaime said, “That gives us A, D, G, L, M, R, S, and Z. The blank spot in the center could represent a vowel, maybe.”

  Theo said, “The D could also represent a vowel. Like an O. But that’s only if this is a transposition cipher and not a substitution cipher. I think we have to assume it’s both, though. Maybe with more than one cipher alphabet.”

  “Sometimes listening to you guys talk is like listening to strange music from a foreign country,” Jamie said. “Weird and interesting, but not something everyone can dance to.”

  “In a transposition cipher, you basically take the letters in your message and just mix them up according to some pattern or scheme,” Tess explained.

  “Yes. But in a substitution cipher, you substitute each letter for some other letter in a cipher alphabet. It used to be that people would use one cipher alphabet to encipher a message,” said Tess.

  “Julius Caesar did a lot of this,” said Theo.

  “It’s amazing how often people like Julius Caesar come up in conversations with you guys,” said Jaime.

  Theo said, “Julius Caesar encrypted his messages with an alphabet that shifted three places to the left, like this.”

  Theo wrote:

  Jaime said, “So, you just stick A, B, C at the end, which stand in for X, Y, and Z?”

  “Right,” said Theo. “If I wanted to use the Caesar shift to encrypt the word high, I would write KLJK.”

  Tess said, “But it turns out that this kind of encryption is easy to break.”

  “For who?” said Jaime.

  “So people had to come up with something that was harder,” said Theo. “You want something hard to break, but easy to translate if you know the way the message has been encrypted. You could make up a cipher alphabet by jumbling up the letters of the alphabet, but unless the person you’re sending the message to has an exact copy of the cipher alphabet memorized, they won’t be able to figure it out.”

  “Couldn’t a computer do it?” said Jaime.

  “I guess, but if the cipher alphabet was totally random, there are something like four hundred septillion possible keys.”

  “Even if you could check one key every single second, it would take a million times the lifetime of the universe to go through all of them,” said Tess.

  “A billion times the lifetime of the universe,” said Theo.

  “Million, billion, whatever,” said Tess.

  Theo ignored her. “But let’s say the cipher alphabet wasn’t totally random, that you jumbled the letters using a certain key word or phrase. Like—”

  “Julius Caesar!” said Jaime.

  “—Ava Oneal,” said Theo. “You write out the key phrase, taking out all the spaces and any repeated characters. Then after that, you write the rest of the alphabet in order.” He wrote:

  “Well, if the key were Ava Oneal, instead of A, D, G, L, M, R, S, Z, we’d have A, E, C, I, J, R, S, Z. That doesn’t seem to work. Three of the letters aren’t even ciphered.”

  They tried Morningstarr for a key. They tried Old York Cipher and then just Cipher. For the heck of it, they tried Theresa and Theodore, Octagon, and Ava.

  The smell of the pastelitos filled the apartment, rich and sweet and doughy. Tess’s mouth watered. Jaime’s stomach growled.

  Jaime said, “What if it’s just a bunch of letters jumbled around?”

  “We could try anagramming them. A computer might help us. Still an insane number of permutations, but maybe we’ll get a hint from an anagram solver site,” said Theo.

  Jaime pulled his phone from his pocket and handed it to Theo. Theo found a site and entered ADGLMRSZ. “Nothing,” Theo said.

  “What if that blank space is a vowel?” said Tess.

  Theo tried that. Again, nothing.

  “Look at the answers that contain only some of the letters. Maybe a partial answer will give us a clue,” said Tess.

  “I have dogma or a dog. Molars.”

  “Speaking of chewing,” said Jaime as his grandmother placed a tray of pastelitos and three glasses of milk on the table.

  “Oh, Mrs. Cruz, these smell so good I could eat the air,” said Tess.

  “I hope you will eat the food instead,” said Mima. “That is the normal thing to do.” She studied their notes, leafed through the pages with all the permutations of the letters, the different keys and alphabets. “You said this Rastafarian cipher—”

  “Rosicrucian,” Theo said.

  “This language of dots,” continued Mrs. Cruz, “was used by silly men in silly clubs. What about the guild that runs the Underway? They are silly. They don’t have any women. And they have secrets to keep, no?”

  Theo said, “People have been questioning the Guildmen for more than a hundred years. They’re not talking.”

  Jaime dropped his pastelito. “Mima, you’re a genius!”

  “Yes, but what’s your point?” said his grandmother.

  Jaime grabbed his phone, punched something in.

  “What?” said Tess.

  “A, D, G, L, M, R, S, Z isn’t a cipher at all.” Jaime flipped the phone so they could see. “These are train routes. All of them are train routes.” He pointed to the spill of coinlike seals on the table. “And these are tokens.”

  CHAPTER TWENTY

  Tess

  Of course Theo asked his usual robot questions: Trains? (Yes, trains.) Where are we supposed to ride them? (Until we find out why we’re doing it.) Should we take Nine? (We’ll leave her with Mrs. Cruz for this one.) How can we be sure of this? (We can’t.) But what do we do once we’re on the trains? (We’ll pay the Guildmen.)

  “Mrs. Cruz gave us the hint,” Tess said. “They’re the ones the Morningstarrs charged with the secrets of the Underway, right? And the clue in this building points to the Underway. I think they’re keeping the secrets of this clue.”

  “People have asked the Guildmen about the Morningstarrs before,” said Theo.

  “Maybe they didn’t ask the right questions,” Jaime said.

  “What are the right questions?”

  Jaime added a few more lines to whatever he was sketching. “Or maybe they didn’t understand the answers.”

  “Who says we’ll understand the answers?” said Theo.

  “We have the tokens,” Tess said.

  But Jaime and Tess didn’t answer Theo’s question about questions or his question about answers, because they were too busy trying to figure out what to do next. They couldn’t take a long ride just then, because it was too late in the day, and because Tess and Theo’s parents would be expecting them home for dinner. And they couldn’t go first thing in the morning either, because they had to spend another morning adding to the teetering piles of boxes and bags filling up their living room, as if Darnell Slant were a train that nobody had the power to stop.

  So, it wasn’t till the next afternoon that Theo and Tess met Jaime in the lobby, and they headed for that first train. They agreed they would take the A train all the way up to the end of the line—or the beginning, depending on how you looked at it—Inwood, 207th Street. They would ride the A train down the length of Manhattan, cross into Brooklyn, stopping at Ozone Park, and then on to Rockaway Beach if they had to. And then they’d switch over to the D train and ride that whole route for as long as it took. Then G, then L, and so on. Since they had more tokens than trains to ride, they would simply offer the tokens to the Guildmen and see what happened. They had not told their parents or Mrs. Cruz the particulars of their plan, understanding that they would never be allowed to travel so far from home, from o
ne borough to the next, through neighborhoods they didn’t know and stations they’d never been to. And they didn’t talk about what they would do if they didn’t have time to complete the routes, or if the Guildmen had no information to offer, or if they simply refused to talk, or if their answers didn’t make sense and would lead exactly nowhere, or if they were all thrown off the train and banned from riding forever.

  They found seats in the front of the train and waited. The stops flew by—people getting on, people getting off—the normal ebb and flow of humanity. Tess wondered how many of them were even thinking about the train they rode, how many of them understood what a marvel it was. How it had been born in the imaginations of the Morningstarrs when most of Manhattan was forests and farms, horses and carriages, muddy trenches where pigs roamed.

  And then she looked at the guildmember in his box, white apron crisp, the wheel symbol of the guild right over the man’s heart. To the Guildman’s right, there was a panel of buttons and gears and levers, but his fingers didn’t touch the mechanisms. Even seated, he seemed large and immovable, stone-faced and stony-eyed, his dark brows drawing to a sharp V shape on the ridge of his skull. Tess had her own questions: How long had he been in the guild; was it a family tradition; did his father and his father’s father and his father’s father’s father keep the secrets of the Underway; and what it would take to reveal them—to her or to anyone? She hoped she could ask him.

  The train quickly passed Central Park, bursting out of the ground at 116th Street and onto an elevated track darning neatly in and out of the tapestry of buildings. People stood in windows of the buildings, drank coffee, laughed, and talked. She was too anxious to sit, so she stood by the doors, rested her forehead against the glass, and looked down where people walked the streets below, brown and black and yellow hair shining in the afternoon sun—168th Street, 175th, 190th. Theo tugged at his lip. Jaime held his sketchbook and pencil but the page remained blank. When the train tunneled into the earth once again and pulled into Inwood, the guildmember’s stone face rolled slowly toward Theo and Jaime and then rolled away, as if they held no more interest than the dog-sized rats that ran up and down the Underway tunnels. Tess’s eyes strayed to the white tile wall just outside the train. Laid into the tiles were the words At the start . . . at long last. She hoped so.