This signal was instantly replied to by the light of a match. The Scoutmaster could see the gleam light up the features of the man Bill. To guard against causing suspicion the fellow was pretending to light a pipe, twice closing his fingers over the flickering match in order to reassure the ex-butler that his message was understood. Tassh waited no longer. He turned and literally sneaked back to his den, none of the Scouts attempting to bar his passage. Another ten minutes passed. There were no further signs of movement on the yacht. The Scoutmaster began to wonder whether 'Tassh's signal was intended to mean that he was suspicious about something, to defer the visit of Bill and his companion in crime until another night. "I wish they'd hurry up," soliloquised Mr Buckley. "I shouldn't wonder if the coastguard boat doesn't turn up soon and nab them. It's a pity. I wish I had told Hayes not to signal quite so soon. The Scouts will only share the fruits of victory, I am afraid." Just then came the sound of a splash in the water. The crew of the yacht had dragged a collapsible boat from the cabin and had launched it over the side. The Scoutmaster waited till the boat was fairly close inshore, then, having made certain that only one man was on board, he silently slipped from his post of observation and rejoined Atherton and the "Otters" in the recess by the mouth of the cave. Grasping Atherton's hand the Scoutmaster, by means of a series of long and short grips, spelled out a message in Morse. "Man coming: tackle him on entering cave." The Leader signified that the message was understood, and passed it on to Phillips, who in turn communicated it to Green and Mayne. Before the remaining "Otters" could be informed, the man from the yacht was heard scaling the cliff between the water's edge and the ledge. With a strange sensation in his throat, Atherton braced himself for the onslaught. He could hear the partially suppressed breathing of his companions and the rapidly approaching steps of Tassh's nocturnal visitor. The patch of starlit sky at the mouth of the cave was darkened by the hulking figure of Bill. Unhesitatingly the fellow advanced into the cave, then drawing an electric torch from his pocket he flashed it ahead to guide his footsteps. The beam of light fell, not upon the sanded floor, but upon the figure of the Scoutmaster standing full in his path. With a muttered oath, Bill threw down the canvas bag, hurled his lamp at Mr Buckley, and turned to seek safety in flight. Up from their hiding-place the "Otters" ran as one man and threw themselves upon the rogue. Bill's fist shot out straight at Atherton's chin, but luckily for the Scout it was light enough for him to see to parry the blow. Down went Bill, struggling and raving like a madman, with his six youthful yet active assailants on to him like a pack of bulldogs.