Based on a true story, the movie is about combat medic Desmond Doss (1919–2006) who was on Hacksaw Ridge with many killed and wounded.

Instead of evacuating the top of the ridge, he remained and rescued 75 wounded soldiers during the night without being detected by the Japanese. He dragged them one by one and lowered each man on a rope down the cliff to other soldiers at the bottom who transported the wounded to base camp.