And then it happened--the thing which Cara had foreseen must almost inevitably ensue. She had a momentary glimpse of the slim naiad figure swaying against a background of sea and sky, then a terrific wave towered up behind it, blotting out the horizon and seeming for an instant to stand poised, smooth and perpendicular like a solid wall of green glass. She saw Ann's face change swiftly as she realised her danger, the upward fling of her arms as she tried to spring to the surface in an effort to escape the full force of the wave and be carried in on its crest. But it was too late. With a crash like gun-thunder the huge billow broke, and to Cara's straining eyes it seemed that Ann's light form was snatched up as though of no more moment than a floating straw and buried beneath a seething, tumbling avalanche of waters. She sprang to her feet and ran towards the water, shrieking for help as she ran. But the noise of the sea drowned her cries so that neither Robin nor Tony, still dressing in one of the tents, heard anything amiss. Even as she called and shouted she realised the utter uselessness of it. No weak woman's voice could carry against that thunderous roar. In the same instant, she caught sight of Brett's head and shoulders in the distance, and she waved and beckoned to him frenziedly. With a choking gasp of relief, she caught his answering gesture before he turned and headed straight for the shore, shearing through the water with a powerful over-hand stroke that brought him momentarily nearer. Though actually not more than a few seconds, it seemed to Cara an eternity before the huge wave which had engulfed Ann spent itself. Then, as it receded she discerned her figure struggling in the backwash, and as the girl at last dragged herself to her knees Cara rushed waist-deep into the foaming, eddying flood in a plucky effort to reach her. But, before she could get near enough, the suction of the retreating wave had swept Ann out of her reach and the next incoming breaker thundered over her again. Cara herself barely escaped its savage onslaught, and as she staggered into safety she turned a desperate, agonised face seaward. Brett was still some yards away, and Ann would die--die with succour almost at hand! Her own helplessness drove her nearly frantic. She was beating her hands together and quite unconsciously repeating Brett's name over and over in a sick agony of urgency. "Brett! Brett! God, let him come in time!... Brett! Brett! Brett!..." The retreating wave revealed once more the slight girl-figure, spent and effortless this time, tossing impotently in the churning backwash. Forrester would be too late! A third wave would batter the life out of that fragile body. Cara's voice died into a strangled sob of despair.