The story is told primarily through the eyes of Stevie Goodwin, a young Marine counting down the days of his service and Frank Castle, a tough Captain with a finely honed killer instinct and survival skills who is described as being "in love with war".

The story chronicles a crucial 4-day period of the platoon stationed at Firebase Valley Forge, a remote strategic outpost on the South Vietnamese-Cambodian border.

Valley Forge is an outpost on its last legs; half of its Marines are addicted to heroin and its commanding officer is an apathetic alcoholic who pretends to have malaria whenever someone comes to inspect the base.

Despite the news that the Firebase will soon be closed, Castle continues leading a squad on routine patrols, though his men are thinned by sporadic ambushes by the Vietcong.

When night falls, bringing a hellish downpour, the Viet Cong and elements of the North Vietnamese Army attack the fortification, using the rain to shield themselves from air cover.

It offers Castle the strength and stamina needed to survive, to maintain an eternal state of vigilance, and to wage a permanent war - at a price.

By the next morning, the air support has returned with an EVAC helicopter to the destroyed encampment, but are horrified to find Castle standing alone in a field of mutilated and broken VC bodies.