Just at that moment Ermengarde almost jumped off the bed, she was so startled by a sound she heard. It was like two distinct knocks on the wall.
"What is that?" she exclaimed.
Sara got up from the floor and answered quite dramatically:
"It is the prisoner in the next cell."
"Becky!" cried Ermengarde, enraptured.
"Yes," said Sara. "Listen; the two knocks meant, 'Prisoner, are you there?'"
She knocked three times on the wall herself, as if in answer.
"That means, 'Yes, I am here, and all is well.'"
Four knocks came from Becky's side of the wall.
"That means," explained Sara, "'Then, fellow-sufferer, we will sleep in peace. Good-night.'"
Ermengarde quite beamed with delight.
"Oh, Sara!" she whispered joyfully. "It is like a story!"
"It is a story," said Sara. "Everything 's a story. You are a story—I am a story. Miss Minchin is a story."
And she sat down again and talked until Ermengarde forgot that she was a sort of escaped prisoner herself, and had to be reminded by Sara that she could not remain in the Bastille all night, but must steal noiselessly down-stairs again and creep back into her deserted bed.
