Douglas Ayr's submarine began an uncontrolled dive toward the massive plain of the seamount at nine hundred feet, leaving her sister vessel, the Helena, as a dark spec against the distant moon-silver surface. "Dive, go after him!" Martin shouted. Having dodged the sinking debris, the Helena started a crash dive. Meanwhile, the sub had gone from tail up to nose up and kept sinking slowly at a thirty-degree angle. The tail hit the barren stone plain...