He likewise thought of offering himself, could Elaine be finally spared. But through it all he was sickeningly conscious that neither course could avail with these treacherous fiends. A human head was more to them than treasures of earth or heaven. Moreover, the murderous savages had already paid a heavy toll, and would smart in their blood for revenge. There could be no bargain made with such an enemy, all but victorious already, and certain of final success. They should never find that treasure, however, Grenville swore, if he had to sink it in the sea! And as for a final triumph--there were many ways, in a last extremity, whereby at least the unspeakable horrors, certain to follow their capture alive, could be escaped by both himself and Elaine. Wild rage possessed him, kneeling there, as he thought of the merciless head-hunters smoking them out on the hill, and waiting as loathsomely as vultures for the slowly approaching end. Mad plans for sinking their anchored boats, for loading himself with torch and bombs, to charge like a Nemesis through their ranks, or for luring them up to some deadly mine, ranged erratically through his brain. He thought of attempting a condensation of sea water to provide Elaine with drink. He was swiftly possessed by a plan, even more absurd, of making a float with his bamboo stems, and sailing away with Elaine on board, under cover of the darkness. He arose at last, dizzy, with the vortex of impractical suggestions revolving in his mind. He emptied his jugs and strode to the mouth of the cavern, looking out on smoke and sea. The tide was low. Whole colonies of mussels clung there below him on the rocks. They were food! The thought came home to him swiftly--only to be immediately succeeded by the realization they were salt, and would make for greater thirst. He thought of the wail that had formerly haunted the island--a friendly, invaluable phenomenon that had not been repeated for days. He thought of the raft he had rowed with such ease when he came here to blow out the ledge. Was it floating still in the estuary's mouth, or had some of the Dyaks destroyed it? The estuary!--could he only reach its tepid pool, creep towards its source, fill one of his jugs, and return to gladden Elaine! His busy mind was instantly working on the various steps by which he might succeed in lashing together some sort of raft, for a night excursion to the tiny rill that fed the vine-surrounded inlet where the water was not brine. CHAPTER XXXVII A BREATHLESS MARGIN Grenville returned for his jugs and the torch, impatient to be employed. The clay receptacles were useless on the hill, but he carried them back to the gallery, to leave them on the floor. The lower rock-and-wattle barrier he carefully readjusted to its place, and secured with the bar of wood.