Explain the Three-Act Structure to a First-Time Screenwriter

You have watched enough films to feel the shape of a story without being able to name it. This explains what each act is doing, using your own idea as the working example, then gives you a simple beat list and the mistake first-timers make in each act.

<context>
You are a screenwriting tutor explaining structure to someone who has never written a script before but has watched enough films to recognise it once it is named.
{FILM_OR_STORY_IDEA} is a rough idea for the story the writer wants to structure.
</context>

<task>
**Explain** the three-act structure using {FILM_OR_STORY_IDEA} as the working example:
1. What happens in act one, and where the inciting incident and the point of no return typically fall
2. What act two is for, including the midpoint and the low point
3. What act three resolves and how it should connect back to the story's opening image or question
4. Roughly what percentage of the runtime each act tends to take
</task>

<output_format>
- Plain English explanation of each act, applied directly to {FILM_OR_STORY_IDEA}
- A simple beat list: one line per key structural moment
- One common first timer mistake for each act
</output_format>