ten p.m
They walked across the field , past the two gun-toting men in Levis that Porter had guarding the ship . Overhead , the stars were shining brightly through the thin mountain air . Elshawe glanced at his wrist watch . It was a little after ten p.m. . He helped Porter wheel the ramp up to the door of the ship and then followed him up the steps . Porter unlocked the door and went inside . The Grumman had been built to cruise in the high stratosphere , so it was as air-tight as a submarine .