Encyclopedia Brown

The Case of the Unexpected Reunion

It was exactly ten'o'clock in the morning on the first day of school at Rushmore Academy and all of the students who were taking cryptography second period that year stood outside their classroom staring at the strange lock on the handle of the wooden door, and waiting for the teacher to let them inside. The class was being held in an old, creepy, adjunct building that sat far away from the actual school and looked almost like a small cottage among the pine trees at the edge of the grounds. Many of the children had never had a class out here before and had thought this building was abandoned. A minute past ten came and class was supposed to have started, but still there was no teacher. A few students had already knocked, but gotten no answer. Then they tried the door, but the lock was on there good, and seeing as how this was the first day and all, no one was quite sure what to do now.

"Is the teacher even in there?" asked a girl wearing a cast on her arm.

"I can't tell if the lights are on," said a boy with big ears.

The students couldn't see anything at all through the building's windows because thick curtains had been drawn closed inside.

"You know if the teacher doesn't show up in the next ten minutes, we're allowed to leave," said a tall child as if it were true.

"Maybe we should try to figure out this lock," said a girl with red hair. "Since the class is all about cracking codes."

She stepped up to the door and took the lock in her hands. It looked like a metal combination lock you would find on a bicycle, but it was gold and had twelve dials with letters on them instead of numbers. Right now they were set to spell out XIBKGLTIZKSB.

"Well, that's clearly gibberish," said the girl to herself, "But, if we use the Atbash Cipher, then X becomes C..." She began to work the first dial until it showed a C instead of X. "And I would be R..."

The other kids watched with confusion as the girl turned each dial, eventually turning XIBKGLTIZKSB into CRYPTOGRAPHY. The lock popped open and the girl was able to open the door and let the other students inside.

"How did you do that?" asked a blonde boy as the students filed in and started to take seats at the desks inside the small classroom. The red-haired girl began explaining.

"Simple," she said. "I just used the Atbash Cipher, one of the oldest substitution ciphers in existence. You just turn the alphabet backwards on itself so that A becomes Z, B becomes Y, and so on until M and N meet in the middle."

"Very good," said an adult's voice from the doorway, and the red-haired girl jumped and turned around to see a tall, skinny man in his late twenties with thick brown hair, brown eyes, and a bemused smile standing there wearing a light blue, button down shirt, a brown, tweed blazer, and gray slacks.

"Who are you?" asked the big eared boy.

"Presumably, he's our teacher," said the red-haired girl.

"Correct," said the man. "I am Mr. Brown, your cryptography teacher," he announced to the whole class, "And you should all thank Ms..."

"Gleason," said the red-haired girl.

"Ms. Gleason," Mr. Brown continued, "For being clever enough to let you in."

The class made a grumbling sound and the red-haired girl smiled.

"It was simple," she said. "I figured since it's our first class you were probably testing us to see if we already knew any cryptography, and if you were going to do that then you'd use one of the simplest codes there is and have the password be something obvious like the name of the class itself, and-"

"Well done," said Mr. Brown. "Perfectly logical guesses."

The red-haired girl smiled even more.

"And where were you the whole time?" asked a dark-skinned boy.

"I was watching you all from the woods," said Mr. Brown.

Everyone, including the red-haired girl, looked surprised.

"I didn't see you," she said.

"Ah, then you all need to work on your observation skills," said Mr. Brown with a smile. Then he closed the classroom door and headed up to the front of the room where his desk and the blackboard were. All of the students had found desks by now and were seated and paying him their full attention.

"As Ms. Gleason was saying," began Mr. Brown, as he started to write on the blackboard with a piece of chalk, "The Atbash Cipher is one of the oldest substitution cipher's in the world. A cipher is an algorithm for performing encryption or decryption —a series of well-defined steps that can be followed as a procedure."

The class began quickly taking down notes in their spiral notebooks.

"The Atbash Cipher was created by the Hebrews...," Mr. Brown went on. He talked and talked for an hour and a half straight and the children hung on his every word. He taught them all about the history of encoding and encryption and was just getting into explaining Rot13 to them when the school bell rang and class had to be dismissed.

"I guess we can pick back up there tomorrow," said Mr. Brown, dropping the chalk into it's tray.

As the children grabbed their things and filed out of the small building, the red-haired girl taking one longing look back at her teacher as she left, a woman with short, dirty blonde hair in a bob cut entered the room. She was also in her late twenties with a firm jaw and light blue eyes that were framed with dark eye makeup. Her lips were painted a rose red and she had just a hint of freckles across her nose. She was wearing a clean, white blouse with dark slacks and a short, fitted, beige trench coat that lay untied and open. For a moment she just stood near the entrance looking at Mr. Brown. He didn't notice her enter because he was gathering up some papers at his desk.

"Not very observant are you, Encyclopedia?" the woman finally said.

Mr. Brown looked up, startled. Then when he saw who it was he looked surprised.

"Sally Kimball," he said, softly, and couldn't help but smile a little. "I haven't seen you in ages."