Round and round spiralled the frail contrivance, tilting with an easy swinging movement as it climbed. Already the monitors looked no larger than toy boats upon an ornamental pond. The irregular ground on either side of the river was merged into an expanse that betrayed no indication of height. Far beneath him Denbigh could discern a ribbon-like strip of silvery-grey. It was the Mohoro River. "Distance lends enchantment to the eye," thought the sub. "And it is such a dirty river." He mused feelingly. In his imagination he sniffed the foetid odours from the torrential yellow stream. He had a mental vision of a swim in the dark, with hippos and crocodiles for company. The reeking mud-flats, too, lay beneath him, their dismal and monotonous aspect obliterated by the charm of altitude. Above the land the rapidly increasing strength of the morning sun was causing great irregularities in the density of the air. The sea-plane rolled violently. Twice she dropped through a sheer distance of a couple of hundred feet, owing to "air pockets", but the pilot, with the utmost unconcern, held her on her course. Presently he turned and bawled something. The rush of the wind made his words unintelligible, but he pointed to the aerial release. Denbigh understood, and depressing the lever allowed a hundred and fifty feet of wire to be run off the reel. Leaning over the side of the fuselage the sub brought his glasses to bear upon the waterway almost beneath him. He could distinguish the fatal bend in the Mohoro River where the _Myra_ had turned turtle and had been swallowed up in the shifting sand. He could even discern her outlines as she lay on her side with ten feet of water swirling overhead. Farther down-stream was something that looked exactly like an island covered with luxurious vegetation. It was the _Pelikan_. The disguise was really admirable. Had Denbigh not known of the means her crew had taken to hide her he would never have detected her presence. But the _Pelikan's_ hour had not yet come. Until the shore batteries and fortifications had been shelled out of existence she was to be left severely alone. With the _Myra's_ crew confined on board the raider, the British monitors dare not open fire upon her. Round circled the sea-plane, gliding down to within five hundred feet of the summit of the mangroves. Everything seemed quiet beneath. The whir of the propeller and the rush of air deadened all other sounds. Here and there were clearings, like to one another as peas in a pod. For the first time in his life Denbigh felt uncertain. Again he swept the river with his binoculars. Across the mud-flats, for the tide was now almost on the last of the ebb, he spotted two slender dark lines stretching towards the navigable channel. A little way down was a series of small dark objects thrown athwart the stream. They were the torpedo-piers and the barrels supporting the chain boom. Almost abreast of them was the screened battery.