The scout followed with the utmost caution--a caution which he redoubled as he drew near to the riverside. He would have thought little of going over the quay wall when the water was up, for that would only mean a ducking, and he could swim like a fish. But in some places patches of deep mud were laid bare at low tide, spots in which the finest swimmer would flounder, sink, and perish. Chippy sought for a mooring-post, and was full of delight when his hands came against a huge oaken bole, scored with rope-marks and polished with long service. These stood in line along the quay some ten yards apart, and Chippy worked from one to the other, and followed his men, who were still ahead, but moving very slowly. It was quite certain that the two in front knew the quay well, or they would not be here at this time. Suddenly a match spurted, and a pipe was lighted. The men had come a good way now from the warehouse, and were quite out of sight of the constable. The light of the match showed the scout that there were two of them, and they had halted in lee of a fish-curing shed, now locked up for the night. The shed stood in a very lonely part of the quay, where no one ever went after nightfall. The men began to talk together, and Chippy crept closer and closer until he could catch their words. 'Laugh!' said one, as if in answer to a remark the scout had not caught--'who could help laughin'? To see old Martin postin' up an' down, round an' round, just on the sides we want him to. If he started to swim up an' down t'other side, now, it might be a bit awkward for us.' 'Ah,' replied his companion, 'it'll be a long time before they tumble to the idea of anybody workin' 'em from the river-front. How did ye get round to the trap this mornin'?' 'Easy as winking,' said the first speaker. 'I made a little errand there, and slipped the bolts, and there it all was, as right as rain.' 'It's a clippin' dodge,' murmured the second man. 'We'll have another good go to-night, then leave it for two or three months till all's quiet again.' 'We will,' agreed the other. 'The boat's ready, I suppose?' 'Yes; I've seen to all that,' was the answer. 'She's lyin' at Ferryman's Slip, just swingin' by her painter. It'll be slack water pretty soon. We can start in about half an hour or so.' CHAPTER XXII CHIPPY GOES IN CHASE Chippy's heart beat high with excitement. It thumped against his ribs till he felt sure that the talkers a few yards away would hear it; and he turned and crept away, and circled round to the back of the fish-shed, where he pulled up to think over what he had heard. He felt sure that he had hit upon the thieves. What should he do? Run to Martin and tell him what he had found out? Chippy considered that, then shook his head. He knew Martin, and Martin knew Chippy. 'He'd ne'er believe me,' thought Chippy. 'He'd think I was a-tryin' to kid 'im.'