The hero must always face a threat and the best way to alert the audience to this threat is to show this threat early in this tory. In “Platoon,” the hero is a new soldier arriving in Vietnam along with another new recruit. They immediately get caught in a firefight where the hero dies but the other new soldier gets killed. That lets the hero (and the audience) know what could happen to the hero.
In “Star Wars” Darth Vader is trying to get Prince’s Leia to reveal the rebel base location. When she refuses, he blows up her home planet using the Death Star. Now we can see the fate of Luke and Princess Leia if Luke should fail to blow up the Death Star.
In “Die Hard,” the terrorists take over the Christmas party and ask the company president to open the vault. When he refuses, they kill him in front of everyone, including the hero. Now we know what fate lies in store for the hero should he fail.
Every story must show early on what fate threatens the hero. In “The Karate Kid,” the villain beats up the hero the first time they meet. Then when the hero pulls a prank on the villain, the villain catches him and nearly beats him senseless until the mentor saves the hero. These two incidents of the villain beating the hero up foreshadows the threat to the hero.
What happens if you don’t foreshadow the threat to the hero? Then when the climactic battle arrives, there’s no sense of dread or tension. In “Suicide Squad,” what’s the big threat to anyone? There are so many characters that the story gets so muddled that you don’t know who to care about. Even worse, you never really see a threat to any of the main characters so you could care less about what might happen to them in the end.
Determine the huge battle at the end between your hero and villain. Once you know the details of this battle, you’ll then know how to foreshadow that threat earlier in the story. By foreshadowing the possible fate of the hero, the final battle is more suspenseful because we already know what could happen to the hero and we don’t want to see that happen. That creates a far more exciting ending than more special effects and explosions could ever do.