A prisoner 'escapes' into a Dreamworld of his own making, where it's always 2:30 am and it's always raining. 2 professional Dream creators are sent in to bring him out before he takes over the AI controlling the country? world? not sure on that. But they have to do it before getting sucked into the story.
If you like the old black and white murder mystery movies from the 40s & 50s, this is loaded with them. Names, titles, slang, descriptions. You name it.
The story is set far in the future where now watching movies is done as Dreams. Or at least I think that's what the Dreams are, since they call old films flatties. And apparently, these future people think that what was portrayed on film was how it was in real life.