Cutbush did not discover his mistake until the others called his attention to it. Then he saw what they meant. Close ahead a triangular promontory of rock and timber jutted in a gradual slope some forty yards beyond the normal line of the bank, and thirty feet straight out from its apex lay the island to which Godfrey had reference. The location was an odd one, and it was a decidedly queer-looking island--a long, narrow cluster of bushy pine trees, pointing up and down stream, and thickly fringed at its base with bushes that seemed to grow straight out of the water. "It's risky to try that passage," said Barnabas, pointing to the thirty-foot channel between island and promontory, whither the flat was now steadily drifting. "We may find shoals there." "I give the rudder a wrong turn without thinkin'," muttered Cutbush. "But it's not shoals I'm afraid of. If we float down yonder I won't have time to steer for the rift through the falls, and they're only fifty yards below." As he spoke he tried to rectify his mistake, and the first two sweeps of the rudder veered the nose of the flat away from the bank. The third swung it broadside across stream, and in this position it bore down on the little island, with a slight diagonal trend toward the wider and safer channel on the outer side. But there was hardly time for this movement to take effect, and the danger of striking was so apparent that Cutbush let go of the rudder--which was as good as useless while the flat was turned broadside--and snatched up one of the poles. He drove it in off the stern, leaned after it till he almost stood on his head, and then rose up with both arms wet to the elbow. "The pole won't touch!" he exclaimed. "There's easy twelve foot of water here." "Twelve foot of water!" cried Barnabas; "an' that island only ten yards below! It ain't nateral, man!" "We're going to strike the island," said Nathan. "Try again." "No, it's all right," interposed Barnabas. "We're movin' slow, an' there ain't any gravel beach as I can see to stick on. The rear end will strike easy, an' then the flat will swing out toward the far channel." So Cutbush dropped the pole and the boat drifted on broadside with the current, its occupants calmly waiting the moment of collision. As the distance decreased from ten yards to five, Barnabas craned his neck forward, and shaded his eyes to peer over the lower bulwark. "It's queer," he muttered. "I've been here before, an' I don't mind seein' that--" Just then a startling thing happened. The whole island was seen to lurch visibly to one side, and at the same instant something flashed and glittered amid the fringe of bushes. "Look!" Godfrey whispered, hoarsely. "Down for your lives, men!" yelled Barnabas. "It's a trap! Keep low, an' don't let 'em get aboard."