Trapped behind enemy lines after fulfilling a mission to sabotage a Chinese invasion fleet intent on starting a war against America, U.S. Army Major Zeus Murphy and erratic fellow officer Win Christian make their way into Vietnam, where Murphy defies orders to save a woman he loves.

Jerry Mitchell, now the commodore of submarine Development Squadron Five, is dismayed when USS Toledo is reported missing in Arctic waters, close to Russian territory. The vessel is captained by his former shipmate and close friend, Lenny Berg. Eager to investigate, Jerry convinces the Navy to redirect one of his squadron's boats to find out what happened. It turns out Toledo was sunk just outside of Russian territorial waters by a torpedo launched...

"While trailing a Chinese nuclear attack sub, Jerry Mitchell, the captain of USS North Dakota, is shocked to see the Chinese boat torpedo a Vietnamese merchant ship. This blatant act of aggression is the opening gambit in a war that has blindsided the U.S. and quickly embroiled all nations in the western Pacific. These nations, bound together in the newly formed Littoral Alliance, have begun a covert submarine campaign aimed at crippling China's economy...