William "Needles" Nelson is a Battalion Chief in the New York City Fire Department (FDNY). He takes the assignment of Chief of the 30th Battalion. He takes over command of Engine Company 99/Ladder Company 62 (Also Known As 62 Truck) alongside Battalion Chief Feinberg, after Battalion Chief Jerry Reilly's heart attack and subsequent suicide. He breaks up a brawl between members of Ladder Company 62 (Also Known As 62 Truck) and visiting Firefighters who are out for revenge after Franco spouts out conspiracy theories about September 11th. He lectures the injured team. Later, he gets into a fight with Franco after the guys watch an interview and Tommy Gavin starts using expletives and obscene gestures. Despite his gruff exterior, he is a good friend who gives advice to his team after rough calls.
