Just then the P.O. telegraphist for wireless duties, who was ensconced in a small insulated cage on the rearmost cutter, received a message from one of the sea-planes to the effect that the Germans had been located. They had landed from the boats at a spot twenty miles above the former anchorage of the _Pelikan_ and were making their way towards the hills. "They're funking it," declared Bourne. "Everything points to a hurried flight. They may have swung the boom back in position, but I doubt the accuracy of your mine theory." "Very good, sir," replied Denbigh. "Then you wish the steamboat to charge the obstruction?" "Yes, carry on," said Bourne. Denbigh was too accustomed to discipline to demur in the face of definite orders. He prepared to cast off the tow, for the steamboat was to essay the feat alone. The two cutters were to anchor until a passage had been cleared through the obstruction. "Well, I hope I'm wrong," thought the sub as he ordered the leading stoker to "let her rip for all she's worth." But before the boat could gather way there was a commotion in the water ahead. A large hippo, frightened by the unusual noises that had disturbed the usually peaceful river, made off up-stream. Swerving neither to the right hand nor the left the huge animal bore down upon the line of floating barrels. It passed between a pair of them. For a moment it seemed that he had surmounted the massive chain, until the sudden displacement of the barrels showed that its body had fouled the hidden barrier. The hippo reared in fury and terror, bringing its whole weight down upon the chain. Instantly a line of waterspouts shot high in the air accompanied by a simultaneous discharge of half a dozen mines. The sudden strain had ignited tubes of fulminate of mercury, which in turn had exploded heavy charges of gun-cotton. Had the boat been a hundred yards nearer not one of her crew would have escaped. In silence Denbigh brought the steamboat abreast of the first cutter and re-established communication. The lieutenant-commander stood up, and in a steady, clear voice exclaimed: "Well done, Mr. Denbigh! My judgment was hopelessly at fault." "That's all right, sir," replied the sub. He knew the effort that Bourne had had to make to tender his apologies. Having given his order in the hearing of the men it was the only course open to him. And Bourne was an officer who, although somewhat impetuous, was never afraid to acknowledge an error. With the flood-tide the flotilla made good progress. Rounding the sharp bend where the _Myra_ had disappeared, the boats entered a gently curving reach that apparently made a long horseshoe sweep. At this point the mangroves ceased. The ground became higher, the banks being precipitous in places, and covered with long rank grass. "There are the _Pelikan's_ boats," reported Denbigh, pointing to two large pinnaces lying against the banks to which they had been carried by the tide.