The climax of the story is when Wyker shoots Jewett and releases Mare from his physical grasp, but not his mental one. She has a psychotic break of her own, and is never the same after the incident.
A climax is a turning point of a story. In a story, the conflict is the struggle between two characters. Mare struggles both with the poetry-reciting madman Jewett and her attraction to him. She is afraid of him and repulsed by him, but in the same way his poetry transforms him, it transforms her experiences with him in her memory.
When Jewett abducts Mare, he seems to be a poetry-induced shapeshifter in his own mind.
'Come!' The arm he put around her shivered against her shoulder blades. It was anger. 'I hate killing. It's a dirty, ugly thing. It makes me sick.' He gagged, judging by the sound. But then he ground his teeth.
The man was an academic once, and he quotes Richard Lovelace and the Old Testament. When the quotes poetry, he becomes the poet and lives the poem. Mare is not Mare or his victim or hostage—she is the subject of the poem. He is clearly educated, but delusional and suffering some kind of psychotic break. The trauma of the incident causes Mare to suffer a break of her own.
When Mare returns home, she is withdrawn. She relives the incident not as a frightened girl dragged through the woods by a psychotic murderer, but as two young lovers.
And the man beside her leaped high over the waves of the dead grasses and gathered the wind in his arms, and her hair was heavy and his was tossing, and a little fox ran before them across the top of the world.
So we see that the external conflict of the struggle between Jewett and Mare was resolved, and the internal one of her fear was, and they have been replaced with this new experience. Often when a person suffers a trauma the person’s brain handles the trauma by inventing an experience that is different, but less painful, than the truth. Some people know this as “repressed memories.” Poor Mare will never be the same.