Episode spoilers.
Sidney Phillips returns to Alabama and reassures Eugene Sledge's parents that their son is safe. On Peleliu, Sledge and the other Marines are struggling with heat, thirst and Japanese fire. Capturing the airfield requires them to cross open ground where there is almost nowhere to hide. Men fall during the advance, and helping a friend can leave someone else exposed. Sledge stops to lift Snafu, only to see the Marine who takes his mortar shot down.
Leckie reaches the far side with Runner, who is wounded again. With the radio operator dead and help urgently needed, Leckie must go back across the same ground to find a working radio. A nearby explosion throws him into a tree and knocks him unconscious. The Marines take the airfield, but many of the men who crossed it must be evacuated. Leckie is carried away from the fighting and placed aboard a hospital ship.
Sledge remains on the island. Haldane acknowledges fear and tries to steady his men, then goes to headquarters to challenge their orders. During the night, a screaming Marine risks revealing the company's position. Attempts to silence him end with a fatal blow, and Sledge's response the next morning is colder than his earlier guilt. Away from the island, Leckie discovers that Runner has also survived. The two sit together aboard the ship and look back at Peleliu, unable to know what has happened to all their friends.