It is the middle of the night after Laura's best day ever. She is sitting at the kitchen table writing a letter:
"Dear Pa, I can't write what's in my heart because I just can't get the words to come out at the end of my pencil. I did a bad thing by having mean thoughts but I know how I can make it right again. I can't tell you the rest, because it's just between me and God. I will always remember today. I love you all. Laura."
She puts the letter on the mantle, says goodbye to Jack and leaves the house. The next morning Caroline finds the letter and shows it to Charles. He can't understand it. He looks around the immediate farm and then calls down Mary from the loft. Mary relates about how Laura refused to pray for her little brother and how she thought Pa only cared for the baby. Charles leaves to start looking for her. He checks the pond and then heads into town. He borrows a horse from Hans Dorfler. Laura is walking through a meadow towards a distant mountain.
Charles rides out to Amy Hearn's where Edwards is working and the two of them begin the search in earnest. Charles is blaming himself but Edwards thinks she'll be home by nightfall. They decide to head back through town and then head east. Laura begins her climb up the mountain. As dusk is approaching, Edwards recommends that they head back to Charles' to pick up lanterns. Laura finally reaches the top of a plateau where she begins talking to God. Laura's plan is to exchange herself for her baby brother. Exhausted, she falls asleep on the rocky outcropping. At the farm, Charles and Edwards stock up on supplies and kerosene lamps and then head out. The next morning, Laura is greeted by Jonathan, who claims to own the mountain she is resting on. She tells him she is looking for God. She is surprised to find out that he talks to God, too. Edwards thinks they ought to double back and head in a different direction. Charles remarks about how cold it was last night and the fact that Laura didn't bring a coat with her.
Laura is getting impatient about hearing from God as Jonathan does some whittling. He asks her about her family and why did she run away but she doesn't trust him enough to tell him, just yet. He hands her a hand carved cross with her name etched on it. It has a string on it so she can wear it like a necklace. He takes her down to a stream where she can wash up.
While she is washing, the cross slips off and floats down the river. Jonathan tells her he will make her another one. He finds a dove with a damaged wing and shows it to Laura. Laura promises to take care of the bird. At the homestead, Charles and Edwards are preparing to go out again. Laura finally confides in Jonathan as to the deal she wants to make with God. Charles and Edwards are at a river crossing. Edwards doesn't think it likely that she would be heading to high country and he recommends that they head downstream. Charles decides to fill the canteens but breaks down. As he slowly recovers, he notices a cross bobbing in the water. He picks it up, notices Laura's name and calls for Edwards. They head upstream.
On the mountain, Laura is waiting for God to answer her. She walks over to Jonathan's lean-to. She doesn't understand why God hasn't responded to her for three days. She thinks she must not be high enough to talk to him. Jonathan suggests doing something to get God's attention and something he can see from afar. He suggests they build a bonfire and so they do. As Charles and Edwards follow the river upstream, Edwards notices some smoke on a nearby mountain and they decide to see where it leads. On the mountain, the bonfire is blazing so Jonathan suggests that Laura go talk to God. She walks down the hill a piece. Charles and Edwards head up the mountain on horseback and then on foot. Laura is talking to God when she hears her name being called repeatedly. She looks down and sees her Pa clambering over the rocks below but she runs back to Jonathan who tells her that this is what God wants. Pa and Edwards finally reach the summit and Laura runs to him. She tells Pa about Jonathan and runs to find him but he is gone. And the dove is gone, too. He hands her the cross that Jonathan made for her. She asks him where he found it and he replies, miles downstream. Pa carries Laura down the mountain as Edwards follows. The dove is seen on a branch and it takes flight.