Far away, on the edge of the Essex marshes and the moon-lit sea, a number of anti-aircraft guns had picked up the raiders. The air was full of a faint, sullen murmur, continuous as the roar of ocean on a distant beach. Searchlight beams, sweeping swift and mechanical, appeared over London, the pale rays searching the black islands between the dimmed constellations like figures of the blind. They descended, rose, glared, met, melted together. The sullen roaring grew louder and nearer, no longer a blend, but a sustained crescendo of pounding sounds and muffled crashes. A belated star shell broke, and was reflected in the river. A police boat passed swiftly and noiselessly, a solitary red spark floating from her funnel as she sped. The roaring gathered strength, the guns on the coast were still; now, one heard the guns on the inland moors, the guns in the fields beyond quiet little villages, the guns lower down the river--they were following the river--now the guns in the outer suburbs, now the guns in the very London spaces, ring, crash, tinkle, roar, pound! The great city flung her defiance at her enemies. Steve became so absorbed in the tumult that he obeyed the order to take shelter below quite mechanically. A new sound came screaming into their retreat, a horrible kind of whistling zoom, followed by a heavy pound. Steve was told that he had heard a bomb fall. "Somewhere down the river." Nearer, instant by instant, crept the swift, deadly menace. A lonely fragment of an anti-aircraft shell dropped clanging on the steel deck. "You see," explained one of the twins in the careful passionless tone that he would have used in giving street directions to a stranger, "the Huns are on their way up the river, dropping a kettle on any boat that looks like a good mark, and trying to set the docks afire. The docks always get it. Listen!" There was a second "zoom," and a third close on its heels. "Those are probably on the _Ætna_ basins," said the other twin. "Their aim's beastly rotten as a rule. If this light were out, we might be able to see something from a hatchway. Mr. Millen (the first mate) makes an awful fuss if he finds any one on deck." "I know what's what, let's go to the galley, there's a window that can't be shut." ... The three lads stole off. Beneath a lamp turned down to a bluish-yellow flame, the older seaman waited placidly for the end of the raid, and discussed, sailor fashion, a hundred irrelevant subjects. The darkened space grew chokingly thick with tobacco smoke. And the truth of it was that every single sailor in there knew that the last two bombs had fallen on the _Ætna_ basins, and that the _Snowdon_ would be sure to catch it next. By a trick of the gods of chance, the vessel happened to be alone in the basin, and presented a shining mark. The lads reached the galley window.