Henry is a young survivor from Hartford who is trying to get his little brother Sam out of hunter-held Pittsburgh. He and Joel get off to a bad start in a brawl, then team up to escape the city, and he fights beside you through the end of Pittsburgh and The Suburbs.
When Joel and Ellie climb into an apartment building to get away from the hunters' armored truck, Henry jumps Joel, thinking he is a hunter. Ellie slashes Henry's arm, Joel beats him down, and only Sam's pistol pointed at Joel ends the fight. Henry decides they are not the bad guys and leads them to his hideout in the Spenzür Architecture offices.
Henry's plan is to slip through the gate at night when only a skeleton crew is on duty. You clear the guards with him, shut off a generator to lure the gunmen down from the bridge, and fight your way to the bridge. When the ladder snaps and the Humvee crashes through the gate, Henry runs with Sam and leaves Joel behind; Ellie jumps back down. Later he pulls both of them out of the river.
Henry holds his own with a pistol and his fists against hunters and infected. He boosts Ellie and Sam through a window to unlock a door in the sewers, helps Joel hold off clickers, stalkers and runners, and draws the sniper's fire in the suburbs while Joel flanks the house.
Sam is scratched by an infected in the suburbs and hides it. The next morning he turns and attacks Ellie. Henry fires a warning shot at Joel to keep him from shooting his brother, then shoots Sam himself. He points the gun at Joel, blaming him, then turns it on himself. Joel and Ellie bury both brothers.
Sam
Sam is Henry's 13-year-old brother, a quiet, anxious kid who becomes Ellie's first friend her own age on the road. You travel with him from the hideout in Pittsburgh through the sewers and suburbs in The Suburbs.
Ish
Ish is a survivor you never meet in person: you learn his story from a trail of notes in The Suburbs, from his wrecked fishing boat on the riverbank to the sewer camp he built under Pittsburgh. Picking up his notes in order tells how one lonely man built, and lost, a community.
Kyle
Kyle is a father from the Pittsburgh suburbs who joined Ish's community in the sewers. In The Suburbs you learn his story from the Looting note and the Cornered note, and Ish mentions him in the Rain catcher note.
Susan
Susan is Kyle's wife and one of the founding families of Ish's sewer community under Pittsburgh. In The Suburbs she appears only in notes: the Rain catcher note written to her and the Survivors note written about her.