Kilometer 31 (Kilómetro 31 or km 31) is a 2006 Mexican supernatural horror film, written and directed by Rigoberto Castañeda.

[3] Following a horrible car accident on a rural wooded road near Mexico City, Agata goes into a coma, and her identical twin sister Catalina begins to experience the pain and terror that her comatose sister is going through.

31 marker and discovers a local legend that tells of malignant spirits that prowl the road and who are said to prey on travellers.

[5] Following a series of terrifying events, Catalina realizes that their link is growing stronger and that her sister is screaming for help from her unconscious state.

[6] With the help of her Spanish boyfriend Nuño, Agata's boyfriend Omar, and local detective Martin Ugalde, she discovers that Agata is trapped between life and death, between reality and a terrible netherworld of evil spirits and ancient legend.