Mark is helping his Pa chop wood. He stops and stares out at the land. If you look quick enough, behind the trees in that scene on the left hand side, you will see someone on horseback hiding behind the trees. I believe this happens right before Mark starts talking about how it seems like they are the only two people there. When the raid starts they are coming from toward the house, not from behind the barn until Chaqua comes and hits Lucas on the head. Cowgirl!
(This picture does not do it any justice, but wanted to give you an idea where to look - if you watch this episode, you can spot it easy).
Also, in this scene, they are on the fake exterior set. But when we see what Mark sees—looking out onto their land, and when the Apaches come riding towards and away from the ranch, these shots were really filmed outside. Thanks Ann Marie!
As Lucas is recuperating in the bedroom, watch the location of the bed. At first, it is almost against the left hand wall. But midway through the scene, after Hattie says, “Lucas, please lie still,” and Lucas sees Sam Buckhart in the doorway, now look at the next wide shot. The foot of the bed is against the right wall! (The same wall as the door!) It’s moved around 3-4 feet! Also observe the chair by the window between these two shots. When the bed is close to the left wall, the chair is big with a rectangular back. (That chair is normally in the main room in season 1.) When the bed’s against the right wall, that rectangular back chair is gone and there’s a shorter, semi-circle-shaped back chair next to the window. Thanks Ann Marie!