The great writer/director Billy Wilder offers this piece of advice on screenwriting and movie making: “Grab ‘em by the throat and never let go.”

This is what your first act, indeed, your first 10 pages must do. This act has several functions. It establishes who your main characters are, the setting, the time period, the theme, genre and tone. It is in this act that we meet the protagonist and the antagonist.

In some movies we may not meet the antagonist directly, but we are at least introduced to them, with hints at ultimate an revelation, such as is often the case in mysteries. Although we may not see them yet, we are made well aware of their presence and the negative, sometimes devastating impact they will have on other characters in the story.

The first act establishes the premise of the story: a cynical saloon owner is shocked to see the woman he loves walk back into his life during World War II. Casablanca. A huge shark menaces a beach community at the opening of the summer tourist season. Jaws. A young fighter pilot must rescue a kidnapped princess and destroy an evil empire. Star Wars.

Your first act must really grab the Hollywood exec by the throat within the first 10 pages or they will stop reading and move on to the next script in the pile.

The first act of a screenplay is generally longer than 10 pages, but that is all the time and space you have to convince someone to keep reading.

Most screenwriting teachers indicate that the first act should be about one-fourth of the entire screenplay. But some first acts are shorter. All first acts must end with the inciting incident, which is an event that happens that either encourages or forces the protagonist to take his or her path in a new direction.

The first act, coupled with the inciting incident, establishes the central question of the story: what does your protagonist want to do, be or have and what or who stands in their way?

Danek S. Kaus is a produced screenwriter with two more films in development, one of them based on a book. Several of his original screenplays have been optioned by film companies. He can adapt your book into a screenplay and also do a Professional Screenplay Analysis