I'm sure you have read about the importance of giving the characters in your novel or screenplay a strong motive, as well as how vital it is to show the behaviour engendered by these motives, rather than just telling us about them.
Recently I ran across a great real-world example of this: "spite houses."
These are houses whose main function is to annoy someone else. Sometimes they block somebody's light or view, sometimes they prevent access, sometimes they are built to mock legal restrictions.
Strong motives in action! How mad would you have to be to build a useless or at least very impractical house?
I'm not suggesting that you have your protagoist build a spite house, but maybe there is an equivalent drastic measure they take that reflects the passionate motive that drives them.
By the way, the spite house shown above was built in 1830 in Alexandria, Virginia. The owner of the homes to its left and right was annoyed that horse-drawn carriages were using the alleyway in between them. He constructed this seven-foot wide house using the walls of the houses on either side.The house is still occupied. (photo credit: shorpy.com)
(Authors who created vivid characters include Jane Austen, Charles Dickens, and Mark Twain. They are among the many whose writing advice I collected and put into my book, "Your Creative Writing Masterclass. It's published by Nicholas Brealey and available from your favorite bookseller.)