Continuing, we know from the prologue that an evil is approaching. From this first sentence, we know that it has arrived. Movement of story. Every element of a story must serve some purpose of advancing the story along its story line. Anything that does not is inert, i.e., dramatically unmoving.
People come to a story with an expectation to be moved on some level.
Stories that fail to move an audience are often set aside. Explanations designed to describe characters and give them a history or to set events into motion along a plot line are irrelevant if they are disconnected from the storyteller's underlying purpose of creating an engaging quality of dramatic movement along a story line. Moving on, second sentence, last line of first paragraph, page one, It was difficult to judge. We have to keep reading to find out. Again note the subtle way the audience is drawn into the story to feel its drama.