But soon the glimmering dawn of an idea did come to him.

The pace slackened, and he noticed that he and Schmidt were falling behind.

The lieutenant called out sharply, and Schmidt, growling to himself beneath his breath, used his spur and brought his horse up into alignment with the others again.

But only for a hundred yards or so.
Then the horse faltered and fell behind again.

Now the lieutenant reproved Schmidt sharply.
"I'm sorry, Herr Lieutenant," said Schmidt.