At almost every third stroke his dripping face flashed up out of the water and his desperate gaze searched the wide expanse for a sight of that ominous fin. Twice he found it; once circling off to the left of where Cavanaugh was swimming, whereat he was thrilled with hope that the creature had abandoned the pursuit. But the next time it was cutting through the ripples straight toward Cavvy, and the sight made Haddon throw caution to the winds.