Across the little channel, mangroves rose from sloppy mud. Their roots were five or six feet high, and mudfish splashed in the holes beneath. Crabs crawled about the roots, for he heard their claws scratch on the smooth bark. He knew the noise; one heard it on board the schooner when the tide was low, and Marston hated the hideous mangrove-crabs that swarmed about the lagoon. They were savage and not afraid. If one sat on the sand, they crawled over one's body and their bite was sharp. A curlew's wild cry pierced the gloom and then all was quiet. Marston frowned. Now the light was going, the forest looked sinister. Perhaps he was imaginative, but his half-conscious shrinking had some grounds. In the tropics the woods were hostile and sheltered man's enemies, of which the insect tribes were perhaps the worst. They attacked in hosts, with poisoned jaws. Then a pale glimmer caught Marston's wandering glance. The tide was creeping across the mud. He went back and stopped at the bridge. Dark had fallen, but the moon was above the jungle and its light touched the channel. The log ran across like a thin black bar, a few feet above the slime. It looked frailer than when he had come. He braced himself, and balancing carefully, went a yard or two along the trunk. Then he heard a crack and seized the creeper as the log dropped under his feet. He held fast, although the strain on his arm was sharp. There was a splash, the creeper broke, and swinging back with one end, he dropped in the mud. It rose to his knee and for a minute or two he splashed and struggled furiously. Somehow he got out and floundered back to the bank he had left. He was breathless and rather surprised to find he had not dropped the gun, but the arm by which he had hung was horribly sore. Then it dawned on him that he was on the wrong side of the channel and could not get across. When he fell into the mud he was not far from the bank, but he had gone deep and it was unthinkable that he should venture farther out. The half-liquid mire would suck him down. Still the tide was rising and he could not stop on the flat. After a few moments, another thing struck him; when he crossed, the bridge, although narrow and slippery, was firm, but now it had given way as soon as it bore his weight. The log had slipped down, or broken, suddenly. He wondered whether it had been meant to break. A few strokes with the cutlass the half-breeds carried would be enough, and he could not have struggled out had he dropped where the mud was deep. Marston clenched his fist and raged with helpless fury. He was persuaded somebody, with devilish cunning, had set the trap for him. When the tide rose the dinghy would drift up the lagoon and in the morning the yacht's crew would find her stuck among the mangrove roots. It would look as if he had landed on a mud bank and had stopped too long. Then, with an effort, Marston pulled himself together. He must search for a place where the bottom was not so soft.