It’s not quite that easy. When I write a story I usually know how it’s going to end, but I have to figure out how to get it there. It’s all about building the tension, challenging your characters, until you’re ready to run the final lap. So how do you know when you’re there?
Remember when we transitioned from your opening to the middle? (If not, you can read it here). It’s time to transition again. Once again, put your main character in a position where your ending is the only option she has. It’s your ending or death (literal or figurative).
Are you writing a romance? Then put your hero in a position where he must choose – he goes after the heroine or the relationship dies. Contemporary fiction? Your main character has to go to Paris or lose his dream job (career death). Suicide? Pay the ransom or the baby dies. It doesn’t matter which genre you write, you can kill something.
Now let’s play my favorite game. Think about your favorite movies/books – can you identify the second transition?
Legally Blonde: Elle has been sexually harassed, her new friend abandons her, and she failed to win back her ex-boyfriend. She wants to leave law school and leave it all behind, but she has to make a choice: let her dreams (and law career) die or stick around and do things on her own terms.
The Lake House: Kate has cut ties with Alex and moved on because, even though she loves him, she thinks he stood her up and doesn’t believe they can make their relationship work . Then she finds out what really happened and she has a choice – continue on her current path or give it up and give Alex another chance.
In both stories the heroines have a dramatic decision to make – one or the other, but they can’t have both. That’s what you need to put in your story – one or the other, a life or death decision. Once you have that in place you can write your ending.