Javier Marías is the omnisicient narrator in the first two chapters, who tells the story from the perspective of Tomas.
In the third chapter, the perspective changes and Berta Isla becomes the narrator, and the subject of her narration is about uncertainty, about what we can know, about what is visible or not, about truth and deception, about following one's heart when there is no longer and present object for that love.
In chapter seven and eight, the omniscient narrator takes over again for the resolution.
Like the other novels by Marías, the lyrical sentences are long, exploring the different conflicting feelings and interpretations that events may lead to, with even more explorations of the ensuing possibilities or needs for action or inaction, resulting in a very realistic depiction of the human psyche in all its hesitating and wavering nature. As usual, and despite the harshness of the plot, the coercion, the absence, the threat of violence, a deep sense of melancholy and sadness permeate the entire story.
Some might find Marías long-winded, but I think his style is utterly enjoyable, and a real treat.