A short distance farther on the party came to an abrupt halt. The rails had vanished. Across the track was a crater twenty feet in diameter, from which acrid fumes were still slowly emanating from the pulverized earth. Already a fatigue-party was at work diverting the lines round the edge of the yawning pit. At all costs communication must be maintained, in order to leave no hitch in the arrangements for the morning's attack.