Complex sentence: In the movie, we only see him trip facedown, hear him let out a terrible scream, as Rainie runs off to get his father, Billy flips him over, and looks in horror as he sees the axe sticking out of Rubin's body.
Split into simpler sentences: In the movie, we only see him trip facedown, hear him let out a terrible scream. As Rainie runs off to get his father, Billy runs over to him and flips him over, and looks in horror as he sees the axe sticking out of Rubin's body.