Once more the voice sounded out of the darkness.
"Mamma! Papa! Mamma!"
"There! Hear it? It's an echo!" cried Freddie.
Flossie listened a moment. Then she said:
"If it was an echo, Freddie, why didn't your voice echo too?"
"Oh,—er—well—'cause I didn't want it to," Freddie made answer. "I can do it now. Hello! Hello! Hello!" he called as loudly as he could.
And then, to the surprise of the children, back came a voice in answer, and in more than an answer, for it asked a question. No longer did the voice call: "Mamma! Papa!"
Instead it cried:
"Hello, there! What's the matter? Who are you and what do you want? Where are you?"
Flossie and Freddie were so startled that, for a moment, they could only hold on to each other in the darkness.