In the book sea of trolls what is a nightmare?

A nightmare, as described in the book "Sea of Trolls," is referred to as "Mare." It's a personified being associated with nightmares and sleep disturbance. The Mare is the embodiment of the dread that comes with the night, creeping into the minds of those as they sleep and causing them to confront their deepest fears and anxieties. It's seen as a malevolent force that torments people, especially children, by inflicting horrific nightmares and restless nights.

In "Sea of Trolls," the Mare is depicted as a creature with dark and mysterious origins, often associated with the troll world. They are said to invade the dreams of the weak-willed, preying on their fears and insecurities. When encountering a Mare, individuals are trapped within their nightmares, left helpless to escape the horrors they face within the depths of their sleep.

The book portrays the Mare as an antagonist, representing the inner demons and fears that individuals must face and overcome to find peace and tranquility. Defeating the Mare can symbolize personal growth and the ability to confront the challenges that haunt one's mind.