"By Jove! if she does come up," thought Barcroft. "It will be Third Single to Perdition for a set of skulking pirates. The fog is lifting, too. I can distinguish the wave-crests nearly a cable's length ahead. We'll be into another patch in another minute, though, worse luck." Suddenly the watchers on the destroyer's bridge caught sight of a short series of flashes slightly on the port bow, and perhaps at a distance of a mile. In a trice Tressidar brought his binoculars to bear upon the glimmer of light, thanking Heaven as he did so that a rift in the fog enabled him to spot the presence of the hunted Hun. The powerful night-glasses revealed the outlines of a conning-tower and twin periscopes just emerging from the waves. Then as quickly as it appeared the light vanished. It was enough. The lieutenant-commander could still discern the patch of phosphorescence that encircled the partly submerged U-boat. "Starboard ten!" ordered Tressidar, at the same time telegraphing for full speed ahead both engines. Before the destroyer could work up to her maximum speed her knife-like bows rasped and bit deeply into the hull of the doomed unterseeboot. An almost imperceptible jar as the quivering vessel glided over her prey, a smother of agitated water on either hand, and the deed was done. Another of the modern pirate craft had been dispatched to its last home. "Voices ahead, sir," shouted the look-out man. "Land ahead! By smoke! We've done it." The engine-room telegraph bell clanged shrilly. As the propeller blades bit the water with reversed action the "Antipas" began to lose way. It was too late. With a shock that threw almost every officer and man to the deck the destroyer charged bows on to a ledge of rocks. Her forefoot lifted almost clear of the water, while to the accompaniment of the hiss of escaping vapour from a fractured main steam-pipe, the "Antipas" buckled amidships. "Clear lower deck! All hands fall in facing outboard!" ordered the skipper. From the mess-deck the "watch below," already roused by the impact of the destroyer with the ill-starred U-boat, came tumbling out, forming up in orderly silence to await further commands. Out of the steam-laden stokehold and engine-room staggered black-faced, partly-clad men, many suffering from the effects of terrible scalds, while others, too badly injured to help themselves, were assisted by their heroic comrades. Risking a hideous death in the partly-flooded engine-room the devoted "ratings" performed acts of valour that, although unseen and unheard of, represent the acme of courage. Fresh from the overheated stokehold and engine-room the survivors of the "Black Squad" found themselves faced with the immediate prospect of involuntary immersion in the chill waters of the North Sea. "Ahoy!" shouted a seaman at the skipper's instigation. "Where are we?" "'Ard aground," replied a voice through the darkness.