Reaching a shaded spot sufficiently isolated for his purpose, he divested himself of his garments, plunged in, and remained for half an hour swimming about idly in the cool water. At length concluding that his bath had been long enough, he drew himself out and was about to resume his clothes, when he happened to glance down the road that led by the canal. About a hundred yards ahead, a black-cloaked figure whose rear view struck him as somewhat familiar, was hurrying stealthily along.
"By St. Pancras!" muttered Gysbert. "If that isn't Dirk Willumhoog again! There's mischief afoot!" Dropping his clothes he ran down the bank, slipped without noise into the water, and swam hurriedly in the direction of the retreating figure.
"If I keep behind him close and to the bank," thought the boy, "I can watch him very well, and he'll never suspect there is a soul around." It did not take him long to catch up with the man he was pursuing. Most of the time he kept out of sight, but he rose occasionally far enough to poke his head over the edge of the canal and peep at his enemy. Once as he did so, he dropped back quickly, finding that Dirk had seated himself under a tree not five feet away. The man was busily engaged in examining the writing on some scraps of paper, or he would certainly have seen the wet, tousled head poked suddenly up over the bank.
"Whew!" thought Gysbert as he ducked, "but that was a narrow escape! I wonder how long he's going to sit mooning there! 'Tis right unpleasant hanging here motionless, and in spite of the heat, the water grows chilly." But Dirk had evidently no intention of moving at present, and Gysbert was obliged to shiver and wait for some time, before the spirit moved the man to be gone. At length the crunch of footsteps on the gravel warned the boy that his enemy was once more on his way. It was a relief to swim again and limber up his stiffened body, but to his astonishment he found that they were drawing near to an unfrequented portion of the city near the walls, and that the canal-street would soon turn off in another direction.
"Where _can_ he be going?" questioned Gysbert, as he poked up his head at the turn, and saw Dirk advancing straight on, apparently right to the wall itself. At that moment the man half turned his head and Gysbert ducked under hastily. When he again raised himself, to his amazement Dirk had disappeared as completely as though the earth had opened up and swallowed him.