Peret’s eyes shone with interest.
“It’s strange that I did not hear this sound,” he muttered, half to himself. “Just what, exactly, do you mean by a whispering sound, Monsieur?”
“I scarcely know,” replied the druggist, after a moment’s thought. “It was a whisper—nothing that I could understand. Just an inarticulate whisper. I had hardly heard it when Sprague screamed and began to struggle.”
“Whence did the whisper emanate, Monsieur?” queried Peret eagerly.
“I do not know.”
“You saw nothing?”
“Nothing.”
“’S damn funny,” growled Strange, scratching his ear. “An ‘invisible monster’ that whispers is a new one on me.” He looked at the Frenchman, perplexedly. “Queer business, Peret.”
“It is,” agreed Peret; then whirled around to confront the pedestrian. “Ah, Monsieur, perhaps you can help us a little, eh? How are you feeling now?”
“Considerably better,” returned the other in a hoarse voice, and then added, “But I don’t believe I’ll ever recover from the shock. What in God’s name was it, anyway?”