The engineer leaped to one of the propellers and swung his weight upon it. The engine turned sluggishly, and then coughed. A second desperate heave. The motor began to run with a roar. The surface of the slime on which the blast of wind beat shivered, and then reluctantly began to retreat. The second motor burst into bellowing activity. The whole plane began to shiver and tremble from the efforts of the powerful engines to draw it forward, but the jelly in which it was gripped still held it fast. The three men redoubled their efforts, and now some faint result began to show. Hampered by the vibrations which strove to shake it off, the Silver Menace advanced less rapidly. In half an hour the upper surface of the plane was nearly free. There was nearly a solid wall of silver horror connecting its under portion with the jellied ocean below. Davis came to the cabin window, wiping the sweat from his forehead. "There's only one chance," he shouted above the roar of the engines. "I've got to fling hand grenades into the sea just ahead of us. They may clear a way for us to rise." Nita silently began to pass him up the small but deadly missiles. Her face was set and utterly pale, but she was rising to the emergency with spirit. An explosion sounded fifty yards away. Another thirty yards away. A third but twenty yards away, and the plane heaved and leaped from the concussion. The blast of air nearly blew the three men from the wings into the waiting mass of animalcules. A huge volume of ill-smelling spume was cast upon the plane, and by its velocity washed away a great portion of the Silver Menace that still clung to it. The propellers dragged at the plane, and it suddenly darted forward down the narrow lane of open water cleared by the three explosions. All three of the men were clinging to struts out on the plane and there was no one at the controls, but Nita bravely grasped the joy stick, and as the end of the open water drew rapidly near she jerked it backward with an inward prayer. The plane lifted sluggishly, scraped the top of the silver sea, and rose. With an inexperienced pilot at the wheel, with the three men precariously balanced on the wings, it headed straight for the broadest part of the Atlantic.