Episode spoilers.
Back on Pavuvu, Sledge rescues a book from Haldane's discarded belongings as the company adjusts to new command. In America, Basilone is tired of being introduced as a hero and travelling to sell war bonds. He asks to work with Marines again and is assigned to train recruits at Camp Pendleton. His first pupils are only two young men, Chuck Tatum and Steve Evanson, before the rest of the new unit begins to arrive.
Basilone meets Sergeant Lena Riggi, a Marine who works in the mess. His fame does not impress her, and an awkward dinner forces him to approach her more honestly. They grow close through time together and their shared attachment to the service. While training continues, Basilone decides to re-enlist and return to combat. Lena understands what the decision means to him, although it will separate them. They marry and take a short honeymoon before he leaves.
The episode then follows Basilone and his men onto Iwo Jima. The recruits he trained must move under intense fire, and he directs them across the battlefield rather than remaining behind them. Their losses mount as he keeps trying to get men through the fighting. Gunfire kills him during the advance, leaving Tatum and Evanson staring at the death of the sergeant they relied on. The closing scene returns to Lena alone beside the sea, at a place she had shared with her husband.