He groped his way round the wall that surrounded the grounds while the dog whimpered and snarled. His wits were moving fast. He had recognised a breed of dog much favoured for police purposes, and he knew that unless he took precautions right away his discovery was inevitable. He made a right angled swerve away from the house. He blessed the dykes that had bewildered him during the day. There must be one somewhere at hand. He must find it before the house was aroused and they turned the dog loose. He tripped over a knot of tufted grass and came down on hands and knees into six inches of water. Recovering himself he pushed forward through mud and weeds into the ditch. It passed through his mind that some of these dykes had water ten feet deep, and that the weeds could baffle the most accomplished swimmer. That was a risk which there was no time to consider. He pushed forward and the mud dragged at his ankles. Behind him he could hear the mutter of men's voices and someone speaking to the dog. In the strange way in which fog sometimes carries sound he heard the snap of the gate padlock and the whimper of the dog as it thudded through in eager pursuit. He was up to his waist by now, and he turned and waded along the stream for a few yards. The wolf-hound drew nearer, and Labar nerving himself dropped to his knees and wondered if it became necessary how long he might be able to keep his head below water. The dog reached the edge of the dyke, and came to a halt whining anxiously. A man's figure loomed up beside him and a moment later two more. "Whoever it was has got across," said a voice that the detective did not recognise. "No use going any farther in this fog." "That damn dog's seeing things," grumbled another voice, and this time Labar identified the tone of Billy Bungey. "If there was anything at all it was a sheep. Who's likely to get out here in a peasoup like this. Call your tripe hound off and let's get inside. I'd got three aces, and I looked like winnin' a pot for the first time for an hour." "Oh, curse your poker," cut in the third voice brusquely. "That dog doesn't make mistakes. Listen." They waited breathing heavily. One of them moved along the dyke in an opposite direction to Labar and looked into its depths. A bullock came out of the fog and peered at him. "There's your ghost," he said mockingly. "And how did he get across the dyke?" questioned another. "Anyway, whoever it was won't come back," said Billy Bungey. "Come on, let's chuck it." The little group moved away, one of them holding the restless hound, and Labar waiting till he heard the gate clang, dragged himself, sodden to the skin, from the ditch. The presence of the Alsatian at the house had complicated matters. If he was to achieve anything on this excursion it had to be dealt with. While it held its vigil within the precincts of the house he could scarcely hope to approach unnoticed.