They swept up to the yacht and circled above it. The junior pilot unshipped the tiny wireless set of the aëroplane, and it crackled busily for a few moments. "All right to alight," he reported. "They say nothing has happened all night, but they're still unable to move." The plane swept around the yacht in a wide circle, coming lower and lower. It was quite impossible to judge where the surface of the water might be, but Davis kept his eye on the deck of the yacht, to get the level from that. At last he made his decision. Being quite unable to tell exactly where the surface was, he could not land in the usual fashion. He slowed in mid-air until the machine was moving at the lowest speed at which it would keep aloft. Then, by a jerk of the joy stick, he headed it upward at an angle it was unable to make at that speed. The result was that the machine stalled precisely like a motor car on an upgrade and, with next to no headway, "pancaked," sank vertically--downward. "Sit tight!" he ordered as the plane sank. Next moment every one of them clutched wildly at the nearest object to keep himself from falling. The plane had struck the surface, but instead of skimming forward, as its slight remaining headway made it try to do, it was brought to a sudden standstill as if by a mighty brake. Only a miracle kept it from overturning. Davis opened a window of the cabin and shouted: "Throw us a rope and haul us alongside!" The men on the deck of the yacht heard him, and a rope came hurtling through the air, to fall across one of the wings. Davis scrambled out and made it fast. Those on the yacht hauled, but the plane did not move. Half a dozen men grasped the slender line and threw their united weight upon it. The rope broke with a snap. "What the----" exclaimed Davis in astonishment. A second rope was thrown. The captain of the yacht called from the bridge: "Haul a heavy line to you and make that fast!" Wondering, those on the seaplane obeyed. The sailors on the yacht made the other end of the stouter line fast to a capstan and manned it. Slowly and reluctantly the seaplane was drawn toward the white vessel. It was Gerrod who looked behind them. Where the float of the seaplane had been he saw a deep depression in the surface of the water, which, as he watched, slowly filled. "The sea is turned to jelly!" he exclaimed, and he was right. They found the truth of the matter when they clambered on board the yacht. With the morning, the members of the crew were able to make a more thorough investigation of what had happened. They lowered boats, and the boats stuck fast. When oars were dipped into the strangely whitened or silvered water the oars were drawn out coated with a sticky, silvery mass of a jellylike substance. From the deck of the yacht the altered appearance of the sea was as remarkable as from the air. All of the ocean seemed to have been changed to a semisolid mass of silver.