Episode spoilers.
Eugene Sledge trains as a Marine while Robert Leckie's unit lands at Cape Gloucester. The men fight Japanese troops in jungle that offers little shelter from constant rain. Even after they survive an attack, their position remains wet and exhausting. Moving through the trees means carrying soaked equipment and trying to sleep in mud. Leckie's anger grows as the days pass, and an argument over possessions taken by an officer brings another punishment.
The violence around Leckie also changes. Gibson strangles a wounded Japanese soldier, and another Marine kills himself in the jungle. These scenes belong to the programme's depiction of the campaign, where the men cannot put their surroundings aside after the shooting stops. When the unit moves to Pavuvu, Leckie still struggles. He begins wetting his bed and is sent to a naval hospital on Banika rather than remaining with his companions at their new base.
At the hospital, Leckie finds Gibson in a separate ward. Gibson explains that he tried to steal an aircraft so he could fly home; his service now appears to be over. Leckie receives rest but wants to return to his unit. He offers his doctor a Japanese pistol to help secure his release. Before leaving, he visits Gibson with cigarettes and tries to comfort him. Leckie can rejoin the Marines, while the friend he leaves behind has no similar departure waiting.