While the three others stood wondering on the dark wharf, the launch
began to draw slowly back into the stream. Already it was riding a bit
low, going down gradually by the bows.

"What now?" questioned the major, astonished.

"She will sink a hundred or two yards from shore, in deep water,"
answered the Master, calmly. "The sea-cock is wide open."

"A fifteen thousand dollar launch--!"

"Is none the less, a clue. No man of this party, reaching the shore
tonight, is leaving any more trace than we are. Come, now, all this is
trivial. Forward!"

In silence, they followed him along the dark wharf, reached a narrow,
rocky path that serpented up the face of the densely wooded cliff,
and began to ascend. A lathering climb it was, laden as they were with
heavy rucksacks, in the moonless obscurity.

Now and then the Master's little searchlight--his own wonderful
invention, a heatless light like an artificial firefly, using no
batteries nor any power save universal, etheric rays in an absolute
vacuum--glowed with pale virescence over some particularly rough bit
of going. For the most part, however, not even this tiny gleam
was allowed to show. Silence, darkness, precision, speed were now
all-requisite.