There was also the possibility--almost the probability--that the strange craft, if a craft it were, might be a British or Allied vessel. In any case, before the _Bolero_ could open fire she had to establish the national identity of the stranger. A Hun was under no such obligation. He could open fire indiscriminately, not caring whether his target were a hostile or a neutral vessel. Again Alec raised his binoculars. By this time the _Triadur_ and the convoy were two or three miles to the sou'east. The _Bolero's_ crew were at action stations, ready at the word of command to let loose every quick-firer that could be brought to bear upon the enemy craft. "What do you make of her?" inquired the Lieutenant-Commander, who, acquainted with the alteration of course, had joined his subordinate on the bridge. Before Seton could express his opinion the question was answered. Two vivid flashes stabbed the darkness, while a few seconds later a couple of shells burst two hundred yards beyond the British destroyer. Almost immediately the _Bolero_ returned the compliment. Her salvo hit exactly on the spot that her gun-layers aimed at--but it pitched into and partly dispersed a cloud of smoke. The wily Fritz had been approaching stern foremost, and directly the German boat fired she went full speed ahead, at the same time releasing an enormous smokescreen. From the British Senior Officer's ship a message flashed: "Stand in pursuit; will remain by the convoy." It was an order after Lieutenant-Commander Richard Trevannion's own heart, and of that of every member of the ship's company. Telegraphing for full speed ahead, Trevannion stood in pursuit. Boat for boat the British destroyer had the advantage both in speed and armament, but already the Hun had gained in distance, and, taking advantage of the smoke screen, was now nothing but an indistinct blur in the night. It remained for the _Bolero_ to keep her quarry within sight, and then the momentarily increasing speed would begin to tell. Firing steadily with her pair of fo'c'sle quick-firers the _Bolero_ held on. Her whole frame vibrated under the pulsations of her powerful engines. The wind no longer whistled through the scanty wire rigging: it absolutely shrieked. At times the for'ard guns' crews were knee-deep in water, as the destroyer literally punched her way through the waves. "A near one, Sir," exclaimed Alec, as a shell burst within twenty yards of the _Bolero's_ port quarter, some of the splinters cutting jagged holes in the two after funnels. Trevannion smiled grimly. "Yes, Fritz can shoot straight sometimes," he replied. "No casualties aft, I hope?" A signalman ran aft to make inquiries. "No, sir," he replied on his return; "the after quick-firer's crew----"