Page 61 of The Resistance Book Club

‘When I send a message, I compose on my piano,’ Theo explained. ‘But the radio needs to be hidden, so I play my own messages on a chromatic harmonica. Others might use a violin or whatever instrument they have. Let me show you how the decoder works.’

The women gathered around him. He produced a sheet of tracing paper with dots on it, and laid it over a Bach piano piece. The larger dots aligned with specific notes, and some of them had smaller dots beside them – one or two.

Theo patiently explained that each dot that aligned with a note represented a specific letter. When Margot and her friends looked puzzled, he told them that he was so used to doing it now that he could decipher simple messages without the decoder. And with a little practice, they’d be able to as well.

Margot was impressed at how ingenious it was, and how skilled Theo was when it came to music. It couldn’t be cracked without both sheets of paper, or the background knowledge of how the smaller dots worked. And it didn’t take a musician to understand it, either, but a musician could add their own complexities to it.

But then Theo started to explain another kind of code, which could be used if all you had was a radio to broadcast it. It wasn’t an existing song or piece of music, but still consisted of notes. If you listened to each one and how long they lasted, they corresponded to a letter; like Morse code. Unscrambling the message was straightforward, but encoding it needed someone who could read music.

‘I’m hoping for a transmission from Daniel himself tonight,’ Theo said. Then he dipped his head and told Isabelle, ‘Your daddy, little one. At last!’

Isabelle giggled at Theo and curled one chubby fist round his collar.

‘And we don’t only use music,’ Theo explained. ‘Those who can, do. But there are a hundred other ways to get messages past the Nazis.’

Nobody spoke as Theo unpacked the radio from its case and turned it on. A hum of static filled the air before the sound of a piano playing started. It was the opening bars of Debussy’s ‘Clair de Lune’. At the sound of the melody Theo whispered, ‘It’s not Chevalier.’

Margot had expected to hear the code come through in music but instead a female voice said, ‘This is Clair de Lune.’

‘Savant,’ replied Theo. ‘I had hoped for Chevalier.’

‘The music will tell,’ said the woman. ‘Commencing in ten seconds, Savant.’

As she counted down from ten, Theo took a notebook and pencil from his pocket. As soon as the countdown reached zero, a cello piece began to play and Theo scribbled the notes down in the book. The women watched him work, as the black notes danced across the paper where the pencil nib scribbled. As the music ended and the low buzz of static returned the woman said simply, ‘Message ends.’

‘Message received,’ Theo replied. ‘Good evening, Clair.’

‘Bonsoir, Savant,’ she said. Then Theo switched off the radio.

There was silence for a moment and Margot thought she felt the chill from the tunnels. She hugged Isabelle tighter. Somewhere, a piano had just played, broadcasting the message.

The women gathered round again as Theo decoded the music, explaining each step as he went. The piece of music was unrecognisable, and would be written anew for each message that needed to be sent. There had been deep, slow notes, fast high notes, and pauses between, as well as notes in the mid-range that alternated speed. Margot had worried that they’dneed to be concert trained and pitch-perfect in order to pick out each note, but, as Theo explained, it made more and more sense to Margot – each note was clearly different and the message emerged:

Liberated Vichy internees in care of Chevalier. Seven souls for extraction via Savant network in next 48 hours. Chevalier extraction confirmed.

A shiver ran through Margot. Isabelle’s father was still out there, risking his life to save others.

‘Extraction,’ said Beatrice. ‘What’s that mean?’

‘It means they’re going to be met and taken to England,’ Theo explained. ‘Esther got so many people out. This will be my first.’

Aunt Sandrine frowned. ‘And the little one?’ she asked. ‘We’ve not talked about that. Will she stay with us, or will she go with her father?’

Isabelle had grabbed Margot’s thumb and was grinning at her. Her huge eyes were full of love, and Margot had adored every moment that she’d been given with the little girl – the baby she and Serge had never been blessed with. But she wasn’t hers.

‘She should go with her father,’ Margot decided. She swallowed, trying to hold down the words that wanted to come out; selfish words, to protest and to keep Isabelle with her. ‘She needs her family, and it’s not safe for her here. She can’t even go outside, poor little thing.’

Beatrice’s lip trembled and she whispered, ‘She’ll come back one day, won’t she?’

‘I’m sure she will,’ Margot said softly, even though she wasn’t sure she could make such a promise.

‘Don’t let her just go,’ Bea implored. ‘We want to saygoodbye before she goes with her dad.’ Then she slipped from her seat and went over to the baby.

Margot realised she wasn’t the only person trying to hold back tears. The other members glanced away, or wiped their eyes. Isabelle had let go of Margot’s thumb and her pudgy little hand gripped Beatrice’s finger. If Isabelle could tell them what she wanted, would she have asked to stay?

The meeting had come to an end, and Claudine cautiously opened the door into the tunnels, listening carefully for any sign that the SS had a patrol down there. Then she turned round to the rest of the book club and gave a thumbs-up; it was safe for them to go. Margot hugged each of her friends as they left. Then she locked and bolted the door, before she and Theo headed up the stairs.

‘Would you like a drink before you go to bed?’ Margot asked him as they reached the first landing and the door to her flat. Isabelle was resting her head on Margot’s shoulder, but she seemed to be resisting sleep.