Martin speaking to Debbie for the first time in five years is a very touching moment.
Martin: Debbie, Debbie, Debbie, don't you remember? I'm Martin, I'm Martin, your brother, remember? Debbie, remember back. ...I do you remember how I used to let you ride my horse? And tell you stories? Oh, don't you remember me, Debbie?
Debbie: I remember, from always. At first I prayed to you: "Come and get me, take me home." You didn't come.
Martin: But I've come now.
Followed up on later when he sneaks into her tent in the middle of the night before the Calvary raid, and she enthusiastically wants to go with him, implying her earlier refusal was really a subtle warning they were about to be attacked.
When Martin immediately stepped between Ethan and Debbie when Ethan pulled out his gun.
Martin: No you don't, Ethan! NO YOU DON'T!
The best part is at the end when Crusty old Ethan, turns out to not be such a bad guy after all.