Without an instant's hesitation he slid the remaining canoe over the grass and into the water, sprang into it, seized a paddle, and started in pursuit. Of course the paddler in the first canoe might be one of the Mantons, but Sumner did not believe it was either of them. He thought it more than likely that the stranger was some one who only desired to try the canoe, but it might be a thief. At any rate, the boy determined to discover who he was, and what he meant by his stealthy performance before they were many minutes older.