‘About another three miles to go,’ replied Burton, peering along the azimuth ring. ‘We’ll carry on like this for another quarter of an hour then before we turn round. Warn the look-outs when we start the run.’ The Torpedo Boat steamed on at about twelve knots to the limit of the area. Her red flag warned all intruders of the nature of her errand, and any passing craft gave a wide berth to the region in which she was working. Presently Burton looked into the compass again and announced that she had reached the turning-point. The _Zero_ swung round on the course for home, and Jenkins bent over the chart. ‘Here we are,’ he said, marking the spot with a pencil, ‘and Raymond dived there. I expect he’ll attack us about four miles this side of the harbour. Our course is 270 deg. Whack her up to full speed and start a zig-zag.’ The telegraph clanged, and the helmsman put his wheel over at an order from Burton. The _Zero_ jumped ahead and began on her erratic run for home. Scarcely a ripple moved the surface of the water now that the light wind had dropped, and the odds were strongly in favour of their spotting the periscope long before Raymond could get into a position favourable enough to fire his torpedoes. With her slender bow slicing up a narrow trench of water the Torpedo Boat raced on, turning and zig-zagging to the slightest touch of the helm. Once Jenkins thought he saw the submarine and gave a sharp order, but it proved to be nothing, and he countermanded it immediately. Then Burton thought he saw her, and after that he saw periscopes everywhere where there were none to be seen. A haunted feeling came over him, and he thanked his stars it was not an enemy boat that was after them. It seemed rather hopeless trying to find her after all. But Jenkins, the veteran, thought otherwise. He had done this job on many occasions, and rather fancied himself at bowling out his submarine friends, and as they approached the suspected area he lowered his glasses and took a final glance at the chart. ‘Keep a good look-out now,’ he shouted to the watching men. ‘Starboard bow probably.’ It seemed impossible that a submarine could approach the little craft and remain undetected. A dozen men were on the alert scanning every inch of the surface in the vicinity of the vessel, and those on the bridge kept their glasses sweeping in all directions. Now that the moment had arrived, an expectant hush fell on the watchers, and each strained his eyes for the first sight of the slightest ‘feather’ or other indication of the enemy’s presence. Even the unnatural behaviour of a gull called for attention, for the wily birds can see and give warning of a periscope long before the human eye can detect it. It was like a game of hide-and-seek, and the look-outs experienced the feelings of a stranger stumbling along in the dark, knowing that somewhere round the corner his enemy is waiting to stick a knife in his back.