made the starting-point of a tunnel to run under the British trench,
and Ainsley had been told off to find out if possible whether this
suspicion was correct, and if so to do what damage he could to the mine
entrance and the miners by bombing.

When his party reached the shallow depression, they moved cautiously
along it, and to Ainsley's relief reached the elbow in safety. Here
they were a good deal more protected from the German fire than they
could be at any point, because from here the depression was fully a
couple of feet deep and had its highest bank next the German trench.
Ainsley led his men at a fairly rapid crawl along the ditch, until he
had passed the point nearest to the mine-crater. Here he halted his
men, and with infinite caution crawled out to reconnoiter. The men, who
had been carefully instructed in the part they were to play, waited
huddling in silence under the bank for his return, or for the fusillade
of fire that would tell he was discovered. Immediately in front of the
crater was a patch of open ground without a single body lying in it;
and Ainsley knew that if he were seen lying there where no body had
been a minute before, the German who saw him would unhesitatingly place
a bullet in him. A bank of earth several feet high had been thrown up
by the mine explosion in a ring round the crater, and although this
covered him from the observation of the trench immediately behind the
mine, he knew that he could be seen from very little distance out on
the flank, and decided to abandon his crawling progress for once and
risk a quick dash across the open. For long he waited what seemed a
favorable moment, watched carefully in an endeavor to locate the nearer
positions in the German trench from which lights were being thrown up,
and to time the periods between them.

At last three lights were thrown and burned almost simultaneously