To craft a compelling story. To gift readers with a moment—a glimpse—into a world so different they're immersed into an alternate reality, but similar enough they can relate. To string a few words that are not new together and create something unique and magical.
Listen to John Irving, Master Craftsman:
CR: Under the Dome by Stephen King. I'm not even 1/2 way through this one. A fabulous story, but I'm finding some POV shifts disconcerting. I'm sure it's my bad, not King's.
It's all better with friends.