By now you should be getting very close to the climax of your story. But before we get there, it’s time to put a barrier in front of your MC’s path. Today have your MC find a way past a guardian.
The “guardian” is a character archetype from the Hero’s Journey presented by Joseph Campbell. The guardian is meant to test the hero before he/she faces a great challenge, and block the entrance to the area he/she needs to go to complete his/her quest. Though the guardian character can appear anywhere in the story, this character works particularly well when leading into the climax.
Christine Frazier from The Better Novel Project refers to the guardian archetype as “the gatekeeper,” and has an excellent article on “How to Transition to Your Story’s Climax with a Gatekeeper,” using examples from Harry Potter, The Hunger Games, and Twilight.
Though many of the examples you’ll find of a guardian/gatekeeper are more applicable to Fantasy or Sci-Fi, any character in any genre can perform this role. The guardian is a great way to introduce a challenge to your MC right before the big showdown; Once the MC passes the “test,” he/she will be ready for the greatest challenge of all.