"Maybe- maybe you've lost your faith in people. But you must still be faithful in something. You must still care about something. Maybe we can't change what is. But trying to save a life isn't wasting yours, is it?"
―Sarah Miller to John Rambo.
Sarah Miller is a sixth-grade schoolteacher and member of the Christ Church of Colorado. She was among the missionaries that were kidnapped by the Tatmadaw when they went into Burma to give aid to the Karen tribespeople. She became one of John Rambo's only friends because she was kind to him and it was because of her that his faith in humanity was restored.
Sarah is one of three women the series to have any dialogue or interact with Rambo in the Rambo series, aside from Co Bao, and the unnamed woman from the start of First Blood.
"We are so close now! What happened here, it's horrible! But people are being killed like this every day. Michael, this was your idea! We made a commitment! I know you don't believe in what we're doing, but it's our choice. Our life. "
―Sarah to Michael Burnett and John Rambo.
Sarah first appears, when she visits the snake farm John Rambo works at with her fiancée, Michael Burnett when he asks if he can taxi them down the river because the Tatmadaw have laid too many land mines on their usual route since their last visit. Rambo refuses, because Burma is a war-zone and it is useless for them to do anything if they aren't armed. However, Sarah talks to Rambo privately and because of her kindness, Rambo agrees to take them down river at no charge. On the boat ride, she is the only person who attempts to start a conversation with him and the two develop a friendship. Later that night, a band of pirates on a boat arrive and order Rambo to hand Sarah over. Rambo knows that they will rape her and kills them all with his Colt M1911 pistol. This shocks Michael and he talks some sense into him when he claims that they would have killed them all and raped her if he had not intervened. Rambo attempts to turn the boat around, but Sarah persuades him otherwise and Rambo agrees to keep going. When they reach their destination, Michael tells Rambo that he will be reporting the murders of the river pirates, because "killing is never right". Sarah, however, thanks him for saving her life and gives him a cross bracelet. A week or so later, Rambo is told by the pastor of Sarah's church, Reverand Arthur Marsh, that he has hired mercenaries to retrieve the missionaries and asks Rambo to be their guide. Rambo agrees and taxis them down river. Rambo kills a drunk Tatmadaw soldier by ripping his throat out when he tries to rape Sarah, and escorts her out of the camp.
When two Tatmadaw soldiers find them, they attempt to kill Sarah, and Rambo jumps in front of her to protect her. Schoolboy, one of the mercenaries, saves them by killing the guards with his suppressed Barrett M82CQ sniper rifle, and they flee the Tatmadaw camp. Rambo leaves Sarah with Schoolboy so they will be safe and starts a massive firefight with the Tatmadaw that frees the missionaries and mercenaries. Sarah is seen embracing with Michael after the battle, and a traumatized and dirty Sarah looks up at Rambo and begins to cry, grateful and shocked at the carnage she has witnessed.
Rambo later goes back to his home in Arizona, finally having moved on with his life, because of Sarah's words.