#Television series don't work like novels.
Television series don't work like novels.
In a popular fiction novel, the tension continually rises towards the crisis where it gets resolved and released towards the end. This traditional story arc* is possible only because the story ends. It is a finite structure. (image source)
In a tv show, especially one that spans several seasons, we don't have a monolithic narrative, but many narrative instances (the episodes) grouped together (into seasons), and both the single episodes and the seasons and (ideally) the whole series have their own narrative arcs. Consequently, there will be many parallel storylines, each with its own phases of rising action, climaxes, and resolutions, that don't all achieve the same intensity, not in parallel, and not necessarily in increasing order.
A tv show, more than a novel, is like a narration of life, and like life, the narration often lacks a coherent structure. Not because the tv show writers don't try, but because the narration itself is potentially infinite and structured into a multitude of narrative acts.
Actually, the situation in books is a bit more complex than traditional narrative theory suggests. Linguistic analyses have found several different types of story arc in fiction. Here is an example (source):