It did not take the children very long to finish all the letters. Peggy had done hers first, so she did Y and Z too, though she was sure they would not want to use the Z.
They had kept their eye on the tower window, but the boy had not appeared again. Now, with the rainy sky, the dark was coming down. A faint light appeared in the distant tower window. For a moment the children saw the outline of a boy’s head and shoulders at the window, and then it was gone again.
“We can’t do any signalling till to-morrow,” said Jack. “What a pity! All the letters are ready!”
Again the next day the children kept a three-hourly watch, and about two o’clock in the afternoon Jack and Nora saw the boy prisoner. He came to the window and leaned out as far as he could.
“He’s looking down into the grounds to make sure that nobody can see him waving to us,” said Jack. “Sensible fellow!”
Jack waved from his window, and the boy saw him and waved back. “Now we’ll do a bit of letter-work!” said Jack excitedly. “Give me the letters I want, Nora, please, and I’ll send him a message. I hope he can read!”
“What message are you sending?” asked Nora.
“Well. I think I’ll just say ‘WE ARE FRIENDS,’ ” said Jack. “Hand me the letters one by one.”
So Nora handed Jack the big letters drawn in black on the white paper. First a big W, then a big E, and so on. The boy prisoner watched the letters eagerly.
He read the words as the letters made them and nodded his head and smiled and waved. Then he began making letters with his fingers - but Jack could not see them so far away. He snatched up the field-glasses and looked through them. The boy began his message again. He held up one finger first.