He left the sentence unfinished, and looked down at the floor with an expression of grim severity that betrayed a momentary glimpse of character. This fighting man loathed and abhorred the thought of an enemy he could not see and come to grips with. Presently he moved over and sat down in the chair between us. Something like a sigh escaped him. Dr. Silence said nothing.

“My sister, of course, is kept in ignorance, as far as possible, of all this,” he said disconnectedly, and as if talking to himself. “But even if she knew she would find matter-of-fact explanations. I only wish I could. I’m sure they exist.”