You’ve got an established story and you’re well into the plot. Perhaps it’s time to add something to jazz it up. Why not bring in an entirely new character?
This character must add a twist to the story, something entirely unexpected. Make this individual’s flaw sufficient enough to alter the flow. Maybe he’s an antique collector who just happened to run across a hidden message at the back of a drawer. The note is yellowed and a bit crumpled, but it reveals….
What if she belongs to a coven and believes that she can influence future events? How could she provide and interesting twist?
The person might have magic or be a descendant of a powerful faerie line. If there was no magic so far in your story, think how this would up the stakes.
Begin by making a list of possible individuals and what they would bring.
Have fun with this one.