Brandon of the Engineers by Harold Bindloss

On reaching camp and reporting himself, Dick was sent to his tent, where he slept until he was aroused by the bustle at reveille. He had not expected to sleep; but he was young and physically tired, and the shock of trouble had, as sometimes happens, a numbing effect. He awoke refreshed and composed, though his heart was heavy as he dressed, because he feared it was the last time that he would wear his country's uniform. The suspense was trying as he waited until the morning parade was over; then he was summoned to a tent where the Colonel and the Adjutant sat.

"I have a telegram asking if you have arrived," the Colonel said in a curious, dry tone. "You must understand that you have laid yourself open to grave suspicion."