Castigo Final (2009)

Eight women convicted for violent crimes find themselves trapped in a prison where there are no rules and where darkness has only one meaning - death. A shapeless executor is killing the convicts in the same way they committed their crimes. As the mysterious deaths mount up, suspicion grows amongst the prisoners. In a race against time, they will have to overcome rivalries and dig back into their past to find the missing link that can set them free. Who brought them there and what for? Will they be able to escape alive? Or will the merciless punisher make them all pay for their crimes?