In which the industrious and enterprising Mr. Astor sets forth two ventures—one by sea aboard the stoutly armed Tonquin, commanded by the steadfast Captain Thorn, and the other by land through the wilderness—with a lively and varied company including the spirited Canadian voyageurs, whose songs and hearty camaraderie lend a poetic air to their hardy labours. The preparations brim with hope and brisk activity, though shadows of mistrust and the tread of political tension mingle with the gaiety, as cautious instructions are imparted to guard against the uncertainties of both man and nature in the vast, untamed regions they are about to explore.