This story by Guy de Moupassant describes a man’s slow descent into madness, convinced that an invisible being he unknowingly lured from a passing ship is preying on his mind. As the entity (supposedly an otherworldly species of vampire that feeds on the life force of those it attaches to) gets stronger, he begins to lose his free will. Unable to flee, he traps it in his bedroom and burns his house to the ground. When this doesn’t work, he contemplates an even more extreme solution. Themes include reality vs. illusion, the unknown/supernatural, terror, madness, despair.