Against the Tide of Years takes place approximately 10 years after the events of the first book. The leadership of the Republic of Nantucket has invested a great deal of time and effort into building up a substantial military force, both a deep-water navy and a Marine Corps, but the bulk of Nantucket's population are more interested in commerce and exploration than in bringing the renegade Walker to justice. A sneak attack on Nantucket itself by the nation of Tartessos, led by an ally of Walker, unites the factions of the Republic behind an all-out effort to topple Walker's growing empire, centered in Achaea (Greece), in a two-pronged campaign, attacking Tartessos and opening a second front in the Middle East (through an alliance with Babylon, Hittite Empire and Mitanni).