Pfc. Eugene Sledge

Eugene Sledge is a soft-spoken young man from Mobile, Alabama, held back at first by a heart murmur while his friends enlist. Bookish, earnest, and devoted to his parents, he finally gets his chance to join the Marines, driven less by bravado than by a quiet, stubborn sense of duty.

Mazzello plays Sledge's innocence without ever making it saccharine, so his gradual exposure to the war lands with real weight. The performance is built on small physical details—posture, breath, the way his eyes track horror—rather than speeches, and it makes him the emotional instrument through which the whole series measures what combat does to a decent person.