"Well?" he enquired laconically, addressing a tall, cadaverous-featured unter-leutnant. "The _Komoran_ is sighted, sir," replied the junior officer. "S19 has just signalled that she is escorting her direct to Stettin. This time, I trust, there will be no mistake." Unter-Leutnant Schwam was referring to the case of a German commerce-destroyer that, having successfully evaded the British patrols in the North Sea, was fired upon and sunk by Hun cruisers in the Baltic under the misapprehension that she was an enemy vessel attempting to run the gauntlet. Since then elaborate precautions had been taken to prevent a similar occurrence, one of which was that commanding officers of patrolling craft were to be on the bridge whenever a German war vessel was passing through the cordon. Having carried out his duties as far as the returning raider was concerned, von Hoppner was about to seek his bunk once more when a vivid light flared from the surface of the water at a distance of less than two miles from the patrolling torpedo-boat. "Donnerwetter!" ejaculated the now furious Kapitan-Leutnant. "Am I to get no sleep to-night? How does that light bear, Herr Schwam?" The Unter-Leutnant took a compass bearing and reported the result of his investigations to his superior. "Then that is at Position 24," declared von Hoppner. "Our section of the defence, confound it!" He rang for half speed ahead, giving instructions to the Quarter-Master to steer towards the burning calcium light that indicated a violent disturbance of the steel net 40 or 50 feet beneath the waves. The "tell-tale" was an ingenious device consisting of a calcium-light buoy made of glass, so as to be practically invisible during daylight. On the under side of the buoy was a "friction-tube" of sufficient strength to resist the power of the winds and currents, but at the impact of a submerged vessel with the net the buoy-rope connecting the latter with the buoy would put a strain on the friction-tube enough to ignite the dazzling light. As V201 proceeded towards the object of her investigations the watch on deck prepared the deadly "distance-charge" grapnel. Over the stern was tossed a length of flexible wire rope, terminating in a cylinder of high-explosive and a barbed contrivance to engage in the net adhering to the trapped vessel. At first only 100 metres were paid out; the rest of the circuit, roughly twice that length, was wound round a drum. "All ready aft?" shouted the Kapitan-Leutnant. Receiving an affirmative reply, von Hoppner ordered speed to be reduced to that corresponding to five knots, and, since the more slowly the grapnel was moving through the water the deeper it sank, the explosive charge was now in a position to engage the obstruction.