A young recruit, Joker, joins the United States Marine Corps and finds himself at Parris Island, where he and his fellow recruits suffer under the brutal training of a severe drill sergeant, Hartman. The recruits endure a grueling regimen designed to break them down and rebuild them as soldiers. Hartman's harsh methods are particularly torturous for two recruits: the witty Joker, who attempts to maintain his individuality under the pressure, and the overweight and mentally unstable Leonard, nicknamed Gomer Pyle, who increasingly struggles with the demands placed upon him. Their relationship with the drill sergeant and each other forms the backbone of their transformation from civilians to hardened Marines.

Transferred to Vietnam as a journalist, Joker witnesses the war's horror firsthand as he becomes entrenched in the chaos and brutality of conflict. He, along with his platoon, including Rafterman, his inexperienced photographer, must navigate the dangerous terrain and the moral complexities of war. Serving in the Tet Offensive, Joker grapples with his dual identities as war correspondent and combatant. The troops confront the enemy on the battlefield while battling their own fears and the morally gray area of their involvement in the war, compelling them to question the purpose and cost of their presence in Vietnam.