A man named Joseph Campbell published a treatise called "A Hero With a Thousand Faces", in it he broke down the archetypes and the structure of the themes permeated through all of our myth. Years later that theme was refined by a writer by the name of Christopher Vogler, he called it the Hero's Journey. It goes like this:
Ordinary World - This is a glimpse at the world as it now stands. Usually this is the part in movies where the hero is introduced and the world is shown to be cursed or unstable. (In Temple of Doom it's where Indy was introduced to the poor village [This followed the teaser, which I'll get into])
Call To Adventure - The Hero is summoned by some calling to embark on a journey...
Refusal of the Call - The Hero refuses the call, becoming the Reluctant Hero. ("We're not heading to Pankot, I need to get to Delhi.")
Mentor - Usually this is where the Mentor Archetype appears, the old wise man that gives the Hero the piece of advice or the focus he needs to leave on his quest.(Marcus - ...It's the Ark. I mean, it's not like anything you've gone after before. Indy - Oh Marcus, I'm going after the find of the century and you're talkin' about the boogy man...) or (You will go to Pankot palace. There, you will find shivalinga and you bring back to us. Bring back to us...) or (Do you believe, Marcus?)
The first threshold - The Hero crosses the first threshold to adventure. He takes his first step into the "Special world" (Indy arrives at Pankot, or in Egypt, or in Venice Indy - Marcus, tell Donovan I'll take that ticket to Venice. Marcus - I'll tell him we'll take two...)
Tests, Allies, Enemies - This is the sequence where the hero is introduced to his friends and his enemies. In Raiders, once Indy arrived in Egypt, he met Sallah. Then He and Marion got into a basket Chase... In Temple of Doom, Indy sat at that unforgettable dinner sequence, where every character to play a part was introduced, except one... In Venice, Indy met Elsa, and the brotherhood of the cruciform sword in a remarkably short time...
This brings us to the beginning of act II. I'll continue more later...