Whose "eyes rolled in the wilderness of his terror"?

That would be the tall soldier (Jim Conklin),

"Suddenly, as the two friends marched on, the tall soldier seemed to be overcome by a tremor. His face turned to a semblance of gray paste. He clutched the youth's arm and looked all about him, as if dreading to be overheard. Then he began to speak in a shaking whisper."

Sorry, I wrote the wrong quote.