I finally broke down and bought the Aaron Sorkin "Master Class" on screenwriting ($90). It's a treasure trove of pertinent information for anyone who has ever attempted to tell a story. The Cliff Notes version: it's all about "intention" and "obstacles" and the competing ideas need to be equal.
Bonus Random Tidbit: "If it's the place you are attracted to, it's a series, and if the characters die at the end it's a feature."
Mickey Free rode deeper into the burned-out canyons, finally topping out on the narrow trail to Divisidero (the Divide).
The problem was he was no closer to finding the Kid than he was when he crossed the border. Still, he pressed on.
"A horse was just a ride to him, and he went through half a hundred in the next few years."
—"The Kid" by Ron Hansen (page 24)