Just as the trio reached the landing, Quackenbaugh ran the prow of his speed boat once more upon the sandy beach.
"Not a sign of anybody around," he exclaimed as he leaped out. "How about the dead man?"
"He's gone."
"Gone?" cried Quackenbaugh, incredulously. Then his features grew tense with the sense of new mystery as he searched first the face of Scanlon and then of Harrington. "The devil!"
Scanlon told him what they had found and of their conjecture; also his decision to keep the matter secret unless publicity should become desirable.
"Right, of course!" approved Quackenbaugh, quick to grasp the salient points. "They're on the island and all we've got to do is to keep them here till Cosby and his men come: to make sure of that I'll continue my patrolling. You three keep together till reënforcements arrive. Then see Miss Marceau safely on her way. Take no chances. We are dealing with desperate characters."
But Cosby and his men found nothing after four hours' search. "They must have had a speeder concealed in some cove and shot away with the body and the gold while Quackenbaugh was on the north side telephoning." That was Cosby's theory. "But my net will pick 'em up before they get very far."
"I must insist on keeping nothing from Mr. Boland," Harrington said to Scanlon and Quackenbaugh, as about sunset they rode back down the channel in the speedboat, three baffled, wrathful men.
"Our strategy just went wrong," snapped Quackenbaugh angrily.
