The idea is really fucked. Basically a killer kidnaps you and puts you inside a cell that you can barely move or breath. And stuck there forever till die. And this twist and turned story about the one who escaped when he was a teenager and trying to hunt this killer as a FBI agent is intriguing, and while it lost me a bit here or there, the ending was really fucked up. Like dark as all hell, but I really enjoyed that part and boosted it from a 3 to a 4 for me.