What he could do then he did not know. But as he tore through the water with that powerful overhand stroke which had won him many a race, his sturdy self-control began slowly to return. Little by little scraps of things came back to him, things he had read and heard, some of them part of that very discussion on the beach so short a time ago. Noise! That was the thing. Sharks were afraid of noises. If he could only reach Cavvy in time there might be a chance—