So I was watching the Hellraiser series, and one of the most underrated films I personally fill is the 5th film Hellraiser Inferno which I'm going to focus on with my question here. In this one, a corrupt L.A. cop named Joseph Thorne opens Lemarchand's Box, and of course it's all downhill form there.

My question is what happens exactly? When the L.A. detective for example in this movie opened the box, from that point on was everything a dream that essentially wasn't real, but was actually happening in hell? Or when he opened that box, was it just opening a gateway to allow hell into his limited world with the cenobites etc.

Are any of the people that Joseph Thorne interacts with after he opens the box actually the real people he once knew, or are they just demons themselves, or just part of the hell world at that point?

Why would anyone open the box then if it puts you into hell? Perhaps the box spoke to Joseph Thorne all along, and it's just symbolic, he was in a living hell he created for himself, but then why do we need the box?.

Can someone please elaborate on this, and also whether or not Throne was supposed to be on earth/in our reality at all once he opened that box, or whether it was all just hell world at that point? Lastly, if he is put into some hell world, what happened to Joseph Thorne's body in our world once he opened the box? Did they just find him dead on the hotel floor where he opened the box, or did he just vanish?