On an island that houses the world's worst criminals, a new prisoner is electrocuted after multiple execution attempts fail and nearly the entire island loses power. He is buried in the prison cemetery under a sign with the number 489. After the funeral, a strong storm occurs and one of the employees goes missing. The remaining two search for their lost comrade and discover that Grave 489 has been dug up, the body has disappeared, and the missing employee has been torn to pieces. Faced with an unknown threat, they must fight for their lives.