“Now I am going to draw two straight lines from the ends of the zones, and they will converge. This, as you might guess, is called the convergence. Pick up your rulers and draw yours, please.”
Dot put up a hand. “How do we know which angle to use or how large to draw the ellipse?”
“Excellent question. The zone varies depending on the length of the signal path and the frequency of the signal. Since this is a hypothetical signal at the moment, there is no wrong answer.”
Dot chose an angle then compared her drawing to Alice’s. They were different, but both illustrated the convergence that Chief Wren Stevens spoke of.
The chief Wren scanned the room, waiting for everyone to finish. “What we just did was give you an idea of what we will be working with. Now we will get to the real thing. Here at Saint-Hyacinthe, we will teach you how to find the coordinates for convergence through specific radio units known as high frequency direction finders, also called HF/DF, or Huff Duff. We will now head out to the hut, and I will introduce you to the radio, your new best friend. Please follow me, and bring your coats.”
Dot placed her hand over her mouth as if she were yawning, but in truth, she was covering her grin. The joy of hearing those sounds for the first time back at Conestoga still felt fresh. It had been like passing into a different universe, sparkling with puzzles to solve. Dot could hardly wait to hear it again. Beside her, Alice gave a little hop of excitement.
In the hut, a dozen desks were set up in a U-shape. Each held a radio receiver and a set of headphones. The receivers were about a foot and a half tall, and their black metal faces were covered in dials and knobs. In the centre was a large circle, and above that at both sides were three-inch rectangular glass windows with numbers behind. Dot’s fingers itched to grab the headphones and slip them over her ears, but she needed to understand everything first.
“This is your Huff Duff,” Chief Wren Stevens said, touching one of the radios. “Your high frequency direction finder. In older systems, if you were trying to determine a bearing, you would have had to mechanically rotate an antenna, then listen. It was complicated and took time that operators sometimes could not spare. Fortunately, the radio before you will only require slight tweaking of the dial.” She indicated a glass pane crossed by a moving sound wave. “A high frequency radio band is what we use to locate or communicate over long distances. You will be able to see the signal on this oscilloscope display.” She looked pointedly at each girl in the room. “Ladies, this is how we hunt U-boats.”
Alice nudged Dot in the ribs, making her squeak. “Here we go!” she whispered.
“Please choose one desk for yourself,” Chief Wren Stevens said, then she waited for all the girls to sit. “When we begin, you will be overwhelmed at first, but I will help you find what you need to hear. After you listen for a while, your brain will pick out the sounds and sharpen them into Morse code. Your job is to translate and write the letters you hear.”
She walked slowly behind the girls’ chairs, leaning in and placing paper and pencils in front of them as she went. “Write what you hear as it comes in. I only want letters from you. Do not, I repeat, do not try to decipher the message. Deciphering is for others who have been specifically trained to break them down, and doing that would demand time we do not have. Only use printed capital letters, please, since handwriting can raise confusion between letters. When you sense the message has come to an end or is repeating itself, put the paper aside to be picked up, then start again with the next message.” She surveyed the room. “All right. Put your headphones on and begin.”
Dot wasn’t overwhelmed. She was euphoric. When the deluge of sounds hit her, she did what Chief Wren Merrivale had done at HMCS Conestoga and fiddled with the radio dial until it all became clear. Listening hard to the air waves, she closed off any other thoughts so her consciousness could drift uninterrupted among the sounds. From her only other experience, she’d learned that cool, unemotional concentration, not thought, fueled the communication. Now, when one sound in particular reached for her, she grabbed onto it and began to print. She heard what sounded like a series of five letters before they repeated. Five, then five more. She printed every one of them in neat, capital letters, then she moved onto the next. And the next. It was exhilarating.
Dot jumped, startled by someone tapping her shoulder. Looking up, she saw Chief Wren Stevens signalling for her to remove the head-phones.
“That’s it for the day. You have excellent focus, Wren Wilson.”
There was no one else left in the room.
The Chief Wren held up some of Dot’s little papers. “Clearly, you have grasped what this is all about. You are a natural, and I am excited tosee how you do after this initial experience. But this is only your first day of listening, and you may not realize it, but you’ve been working for two hours straight, not even pausing for a sip of water. It’s time to stop for the night.”
You are a natural.The words of acknowledgement made it easier for Dot to set the headphones aside, though she wished she could just keep going. A natural? Yes, I am! she thought, energy buzzing through her. When she reached the barracks, she barely remembered walking there, but she knew she was wearing a ridiculous grin the whole way.
Day after day, she plugged herself into the sounds, feeling like a race car starting its engine, impatient for the finish line. Sometimes the letters came in groups of three, sometimes in pairs, sometimes five in a row, and Dot wrote every one of them down. They rarely spelled anything or made any sense, but she knew to expect that. The hours were never long enough for her. This wasn’t work; it was energizing. In contrast, the other girls threw themselves onto their beds at the end of every day, worn out. Even Alice complained that all she could see and hear these days were dots and dashes.
“I am dit-dit-dit-dit done!” she groaned, climbing into her bed at the end of the second week. Her bright curls tumbled over the edge of the upper bunk when she leaned over to look at Dot. “That’s all I hear now!” she cried, a wild sort of light in her red-rimmed eyes. “The pipes clank, and I hear a message. The springs of this”—she bounced slightly, jarring the bunk—“mattress are talking. Do you know, I was waiting for the kettle to boil today for tea, and I found myself listening to the sound of the steam and trying to hear dits and dahs. I don’t know how much more of this I can take!”
Dot felt no such strain, but she didn’t want anyone to think she was strange—like when she had recited double-digit multiplication tables in grade four and all the other children had stared—so she didn’t let on that this was her idea of fun.
“We’ve made it this far, Alice. There’s nothing we can’t do, remember? Don’t give up yet. There’s a lot more coming.”
Alice made an agonized noise of frustration as she flopped back onto her pillow, disappearing from view. “Da-da-dit Da-da-da Dit-dit Da-dit Da-da-dit Da-dit-da-dit Dit-da-dit Dit-da Da-Da-dit-dit Da-dit-da-da!”
Dot smiled, translating her friend’s noises. “Going crazy.”
Dot loved what she was doing, but as time passed, she realized it wasn’t enough. She could hear the Morse code beeping through her headset, but what was itreallysaying? After a while, despite the warnings, Dot gave in to the siren call of the letters. It was obvious the various combinations were puzzles. Other people had been trained to decipher them, but Dot could see no reason why she couldn’t try as well. While she was hunting for a new message, why couldn’t she spend a little time sorting through the last one, to see if she could figure it out.
Three hours into her next shift, she decided to try. She wasn’t doing anything sneaky or against the rules, just playing with letters a bit on the side while she listened for more. She slouched in her chair, rubbing the back of her stiff neck, and stared at the letters she’d just written.
These had arrived in a series of four at a time. Like most of the thousands of letters she’d written, they appeared to be arbitrary. But through all her listening, she’d picked up patterns, and she was certain she had heard these ones before. Between incoming messages, she bent over her desk and wrote different combinations of the same letters, trying to make something come together.
B-O-E-J
F-H-S-V
Q-Q-F-X
The double Q seemed suspicious. A possible clue, if she could parse it correctly. Especially since there was no letter U in the message. Maybe each line was separate but backward. JEOBVSHFXFQQ. Or maybethatwas backward XFQQVSHFJEOB. JOB SHE, she wrote, mixing up the letters then crossing them out. Obviously it was a code, but what was the key to unlocking the meaning? She assumed the Germans would constantly change the keys around; the people doing thedeciphering had them and would know which to use, but she’d get no hints.
