Hurtled through time and space from the World War II Pacific, Lieutenant Commander Matthew Reddy and the crew of the USS Walker find themselves in a strange alternate world where they ally themselves with the Lemurians in their battle against the warlike reptilian Grik.

After the battle in which the men of the destroyer Walker and their Lemurian allies repelled the savage Grik, Lieutenant Commander Matthew Reddy is shocked by the arrival of a strange ship captained by one Commaner Jenks of the New Britain Imperial Navy. As tension between the Allies and the Imperials mount, Reddy will come to realize that his suspicions are not misplaced, and that a greater danger than the Grik is closer than he ever suspected.

Matt Reddy sets off in pursuit of a rogue Japanese destroyer, the Hidoiame, while the invasion of Grik "Indiaa" begins with the Human-Lemurian Alliance fighting against the Dominion.