Only a rocket scientist could understand the physics behind Star Trek V: The Final Frontier, but it doesn't take one to comprehend its plot. A straightforward affair, the film focuses on one primary storyline, with a few parallel side plots peeking through at times.
For the bulk of the film, we follow the crew of Enterprise. We see them on shore leave, we see them attempt a hostage rescue on Nimbus III, and we see them journey to the center of the galaxy. This primary plotline progresses in a straightforward fashion, and though there are a few twists and turns along the way, it rarely deviates from this course.
There are a few parallel side plots, however. Before the crew reaches Nimbus III, for example, we watch Sybok spread his intergalactic cult across the planet. Likewise, we meet Klaa at the beginning of the film when he decides to hunt Enterprise, even though he doesn't factor in to the plot until its closing moments. In both instances, however, these side plots relate back to the main storyline in obvious ways.