Steve’s feet were on the plank before the meaning of the words stung into his consciousness. As he ran, his startled gaze swept over the glinting water and for an instant his blood froze. Beyond the struggling Cavanaugh, but much nearer to him than the latter was to shore, something thrust up above the water—something thin, triangular, erect, dull gray in color, that cut through the little waves with swift, smooth, gliding ease.