Warren is a Firefly fighter and friend of Marlene whom you see captured by FEDRA soldiers in The Quarantine Zone, under a bridge along the Boston waterfront.
After Joel and Tess agree to Marlene's deal, they follow her along the waterfront to a heavily patrolled area under a bridge. Climbing a staircase, they see Warren held at gunpoint.
The soldier shoots Warren in the head. Once Joel, Tess and Marlene clear out the guards, Marlene stops by his body to say goodbye until Joel tells her they have to keep moving.
Marlene, nursing a gunshot wound, steers Joel and Tess through the docks around patrols still hunting the Fireflies who bombed the checkpoint that morning. She tells them the Fireflies only want out of the city and are fighting back because the military stirred them up.
Ellie Williams
Ellie Williams is the 14-year-old girl Joel is hired to smuggle out of Boston, and your companion for most of The Last of Us Part I. She was bitten weeks earlier and never turned, so the Fireflies believe her immunity could lead to a vaccine. You play as her in the winter chapter and in the Left Behind DLC.
Joel Miller
Joel Miller is the man you play for almost all of The Last of Us Part I. A hardened smuggler in the Boston quarantine zone, he takes a job escorting 14-year-old Ellie out of the city, and the drop-off turns into a year-long trip across the country to find the Fireflies.
Malick
Malick is a tough in the Boston slums who tries to block Joel's path in The Quarantine Zone. Tess knows him and sends him back to his seat with a single word.
Mark
Mark is a Boston quarantine zone resident who is only talked about. In The Quarantine Zone, Joel can overhear Ronnie telling a friend that soldiers caught Mark using fake ration cards.