When an experimental lethal-injection has the unexpected result of making an inmate immortal, the most vicious convicts steal it to take over the prison and the world.

In an abandoned mental institution, doctors carry out secret experiments on unsuspecting patients. The experiments, codenamed Limes, are designed to cure violent episodes within the inmates through new methods of brainwashing and mind manipulation. It is soon discovered by the families of the patients that this is no ordinary hospital.