In obedience to the Sub's order, a man made his way aft and paid out the patent log-line. The mileage as recorded by this instrument and the course as determined by the magnetic needle were the sole factors used to take the M.L. to her appointed station, four miles from a prominent headland and right in the steamer-track of vessels proceeding northwards from the Firth of Forth. Kenneth felt no particular enthusiasm for this kind of work. It was Duty, spelt with a capital D. Whether the patrol were essential to safeguard shipping had yet to be proved. For the best part of a twelvemonth M.L.'s were constantly on duty off the headland, yet on no occasion had a U-boat been definitely sighted. There had been false alarms. A boat-hook stave floating perpendicularly and drifting with the tide had caused the waste of a couple of depth-charges and incidentally the slaughter of thousands of fish; a derelict fore-topmast had been responsible for the expenditure of twenty rounds of six-pounder ammunition. On the other hand, what might have happened had the Auldhaig M.L. Patrol not been in existence can well be conjectured. The slow-moving tramps chartered by the Admiralty to take naval stores to the Grand Fleet at Scapa Flow would have afforded easy targets to U-boat commanders but for the constant vigilance on the part of the M.L.'s. In effect, the little patrol boats had frightened off the modern pirates, thereby performing a useful though somewhat monotonous rôle in the question of Sea Power. "'Tany rate, I'm afloat," soliloquised Meredith. "Better than sitting tight in a muddy trench and being strafed day and night by Boche artillery; but I wish to goodness I'd been in the Dover Patrol. There's no Zeebrugge this end of the North Sea to make things a bit lively." "Wireless message, sir." Meredith turned abruptly to find an operator proffering a leaf from a signal pad. "Anything important?" he asked. The lad--he was one of the two ex-bank clerks--smiled. "Looks like business this time, sir," he replied. "A U-boat's been shelling Aberspey. One of our blimps nearly got one home, and Fritz sheered off and was lost in the mist." Switching on an electric torch, Meredith read the message. It was couched in matter-of-fact official terms and left much to the imagination. Briefly, the U-boat was believed to be damaged and incapable of submerging. It was last sighted at 22.30 (half-past ten), steering eastward and apparently on fire aft. "Very good; inform the skipper," said Kenneth. "Yes; we stand a chance of seeing something this time." In less than a couple of minutes Wakefield was on deck.