“Why? Because every wave that comes in swells over where we’re standing, and rushes right into the cave. You wait and you’ll hear it boom like thunder.”

Plosh!

“What’s that?” cried Max, catching at his companion’s arm.

“My seal! You watch and you’ll see him come out.”

“Yes, I can see him,” cried Max, “swimming under water. A white one—and—and—Why, it’s that boy!”

“Ahoy!” cried a voice, as Scoodrach, who had undressed and dived in off the shelf to swim out with a receding wave, rose to the surface and shook the water from his curly red hair.

“Well, he can swim like a seal,” cried Kenneth, running along the rough shelf. “Come along.”

Max followed him cautiously, and with an uneasy sense of insecurity, while by the time he was at the end his guide was undressed, with his clothes lying in a heap just beyond the wash of the falling tide.

“Look sharp! jump in!” cried Kenneth. “Keep inside here till you can swim better.”

As the words left his lips, he plunged into the crystal water, and Max could follow his course as he swam beneath the surface, his white body showing plainly against the dark rock, till he rose splashing and swam out as if going right away.