In the course of time this occupation defeated its purpose; the very
monotony of it sent his thoughts winging back to Quain; he worried more
than ever for his friend, reproaching himself unmercifully for that he
had suffered him to go alone--or at all. Quain had a wife and children;
that thought proved insupportable.... Had he missed the catboat
altogether? Or had he gained it only to find the motor disabled or the
propeller fouled with the wiry eel-grass that choked the shoals? In
either instance he would be at the mercy of the wind, for even with the
sail close-reefed he would have no choice other than to fly before the
fury. Or had the boat possibly gone aground so hard and fast that Quain
had found himself unable to push her off and doomed to lie in her,
helpless, against the fulling of the tide? Or (last and most grudged
guess of all) had the "skimmy" proved as unseaworthy as its dilapidated
appearance had proclaimed it?

Twenty minutes wore wearily away. Falling ever more densely, the snow
drew an impenetrable wan curtain between Amber and the world of life
and light and warmth; while with each discordant blast the strength of
the gale seemed to wax, its high hysteric clamour at times drowning
even the incessant deep bellow of the ocean surf. Once Amber paused in
his patrol, having heard, or fancying he had heard, the staccato
_plut-plut-plut_ of a marine motor. On impulse, with a swelling heart,
he swung his gun skywards and pulled both triggers. The double report
rang in his ears loud as a thunderclap.

In the moments that followed, while he stood listening, with every
fibre of his being keyed to attention, the sense of his utter isolation
chilled his heart as with cold steel.

A little frantically he loaded and fired again; but what at first might