IMDB summarizes it as: A novelist struggling with writer’s block finds romance in a most unusual way: by creating a female character he thinks will love him, then willing her into existence.
What I love about movies about author’s actively writing books is that there’s always the undertone of “is it real, or is it the story of the story they’re writing” and with this movie in particular trying to figure out what’s real and what’s fiction makes it an even more interesting movie to watch.