The Ebb Tide

Deep beneath the quicksands of Morecambe Bay lies a shifting graveyard of lost things, long sunk to the sea bottom. Pursued by the nefarious Dr. Narbondo, Langdon St. Ives and his stalwart companions descend beneath the sands in a diving chamber, and amid the debris of human bones and the wreckage of human lives, they search for an alien device, which, in the wrong hands, could change the course of human history and provide Narbondo with the means to enslave mankind....