Ray Breslin (Sylvester Stallone) wrote the book on breaking out of prisons. That’s not a metaphor, as almost every character in this film has read the book, and keeps a copy of it nearby for dramatic effect.
Ray makes his living by stress-testing maximum security prisons. Disguised as a convict, Ray is inserted into prisons so that he can break his way out, and then identify the security flaws. He’s broken out of every prison he’s ever been inside, and he’s confident in his abilities.
When a secret black-ops prison needs testing, they come to Ray. And they come prepared to pay a large amount of money for his services, particularly if he overlooks normal security procedures. As you might imagine, it turns out that this prison is both more secure and more evil than other prisons, and now he has to break out for real.