Colebrook felt with his hands on the ground: "I can make out the spoor!" he muttered, after a minute.

"He has gone on this way!" We tracked him a little distance in, crawling at times, and rising now and again where the runs opened out on to the air for a moment.

The spoor was doubtful and the tunnels tortuous.

I felt the ground from time to time, but could not be sure of the tracks with my fingers; I was not a trained scout, like Colebrook or Doolittle.

We wriggled deeper into the tangle.