As in a panorama, he saw the emergence of humanity from the animal stage, the primitive savagery of his kind; then the beginnings of the family, the nomadic epoch, the stone age, and the bronze age, and the age of iron; the struggle up to agriculturalism, and communism, and the beginnings of the village groups, with all their petty tribal wars. He saw the slow formation of small states, the era of slavery, then feudalism and serfdom, and at last the birth of modern nations, the development of machinery, and the vast nexus of exploitation known as capitalism--the stage which at one blow had been utterly destroyed just as it had been transmuting into collectivism. And at thought of this Stern felt a pang of infinite regret. "The whole evolutionary process wiped out," mused he, "just as it was about to pass into its perfect form, toward which the history of all the ages had conspired, for which oceans of blood had been spilled and millions of men and women--billions!--lived and toiled and died! "All gone, all vanished--it's all been in vain, the woe and travail of the world since time began, unless she and I, just we two, preserve the memory and the knowledge of the world's long, bitter fight, and hand them down to strong descendants. "Our problem is to bridge this gap, to keep the fires of science and of truth alive, and, if that be possible, to start the world again on a higher plane, where all the harsh and terrible phases will no longer have to be lived through again. Our problem and our task! Were ever two beings weighed by such a one?" And as he pondered, in the firelight, his thoughts and dreams and hopes all centered in the sleeping girl, there in the lean-to sheltered by his watchful care. But what those dreams were, what his visions of the future--who shall set forth or fully understand? CHAPTER XV LABOR AND COMRADESHIP Four days later, having hastened all their preparations and worked with untiring energy, they broke camp for the long, perilous trek in quest of the ruins of a dead and buried city. It was at daylight that they started from the little shack in the edge of the forest. Both were refreshed by a long sleep and by a plunge in the curling breakers that now, at high tide, were driven up the beach by a stiff sea-breeze. The morning, which must have been toward the end of September--Stern had lost accurate count but reckoned the day at about the twenty-fifth--dawned clear and bracing, with just a tang of winelike exhilaration in the air. Before them the beach spread away and away to eastward, beyond the line of vision, a broad and yellow road to bid them travel on.