As they went on with these preparations, looking to the repulse of invading hosts of sleek gray-coated beasts of prey, they could hear the fiendish chorus of wolfish howls drawing steadily nearer all the while. There may have been a lingering doubt in the mind of Jack or Harry concerning the accuracy of that guess on the part of Amos, but it was gone by this time. Those constantly increasing howls had convinced them beyond all question.