An epiphany is the moment when everything suddenly makes sense to the character. In short, it is the character’s revelation.
Have you ever been struggling with something for a long time and suddenly (one day, out of the blue, when you least expect it), the answer comes to you? This is the kind of moment I’m talking about giving your character.
For example, in the book (and movie) Gone With the Wind, Scarlett spent the entire time trying to get the perfect man. She believed this man to be Ashley. What she realizes, at the very end, is that the perfect man was really Rhett, and he’d been there all along. That was her epiphany. I’ve seen the movie and the book, and they end the same. (Hint: if you’re a die-hard romance reader who loves a happy ending-skip this one.)
The epiphany is the “a-ha” moment when everything finally makes sense to the point of view character. It’s the moment when all the pieces of the puzzle have finally fallen into place. The character now knows how things are either working for, or against, her. In return, she will have to take appropriate action because of it.
The epiphany usually happens around the climax of the story, but it can happen earlier. If it happens earlier, the character will then have to take steps in light of this new information that will lead to the climax where things can be resolved.
For example, your character might find out he has a terminal illness. He realizes he’s wasted his entire life on worthless pursuits. Let’s say this epiphany happens at the beginning. As a result, the character decides he is going to make each moment count, and might, along the way, bring joy to other people who are in need. At the end of the book, the character will feel complete in knowing he made his life count.
Or, if you want to put an epiphany at the end using the same plot idea, the character will find out he has the terminal illness, BUT he’ll struggle with finding meaning to his life before he dies. He spends the book coming across all sorts of different people. However, it’s not until he’s on his death bed that he realizes he has impacted the lives of those people. When all the people are gathered around him, his epiphany could be at the moment he realizes his life had meaning after all.
So the epiphany is something that’s flexible and can easily work its way into the story at any point in the story. The key is to put it where it has the biggest impact for your character.