A fair, delicately-molded hand, on which glittered gems worth a raja's loyalty, was extended in the direction of the sea. Half a mile out, where the light ripples melted away into a blue and white haze upon the water, a small black smudge, like the back of a porpoise, seemed to be sliding along the surface. But it was not a porpoise, for out of it there rose a thin, black shaft, scarcely higher than a flag-staff, and from the top of this thin shaft there trickled a faint wreathing line of smoke, just visible against the background of sky and sea. "It is a submarine! What is it doing there?"