Blood Curse (Portuguese: Coisa Ruim) is a 2006 Portuguese supernatural horror film directed by Tiago Guedes and Frederico Serra, which talks about demonic possession, exploring beliefs, superstitions, skepticism, fears and suspicions, in the context of a small village.

Xavier Oliveira Monteiro (Adriano Luz) is a botanical researcher and university professor.

One day Xavier receives news of the death of his uncle, owner of a family manor in a village in the municipality of Seia.

On arriving at the village, he becomes friends with the locals, whom he perceives to be very superstitious and believers in matters related to the occult.

At first Xavier tries to ignore it, but strange events with no logical explanation, but coinciding with some local beliefs begin to occur to him and his family.