This is a classic principle of gripping screenwriting.  You create more drama in a scene if you enter it with some action already underway. You avoid the boredom of a drawn-out conclusion if you leave it once the action is done (preferably even adding another hook to the next scene).

Exercise:

Write a scene that starts slam bang wallop in the middle of the action. No introduction, no back story. Use what you’ve learned in previous exercises about character, description, and action to fill in any details we need.

Click the little blue frog to post your exercise.