I don't often have dreams about books I read, but I had a dream about Final Crisis after I read it. In the dream the squad of supermen from across the multiverse discover that Darkseid has a secret base at the bottom of the ocean. They plunge into the ocean to attack, but as they dive deeper and deeper into the murky depths they start to drown. The final image of the dream was Billy Batson lying dead on the ocean floor.
In Final Crisis Morrison tries to take the concept of superheroes to all new depths and in the process nearly drowns it. Before the story begins we are told that a cosmic war has taken place and the forces of evil have won. The evil gods are incarnating on Earth in human form for some reason, humanity is being brainwashed into a state of hopeless despair called "anti-life," and the heroes are being corrupted or killed one by one. It is about as bleak as mainstream comics gets.
A bad rap that gets hung on Morrison is that his writing is confusing. I am usually quick to defend his storytelling, but this time I have to admit I was confused by the ending. Spoiler warning here of a sort. There seemed to be several endings piled on top of each other. Maybe Morrison is trying to make the ending like a legend that can have contradictory details. I'm not sure if the heroes transported humanity to an empty alternate reality and started over, or if Batman succeeded in taking down Darkseid, or if the multiversal cavalry arrived in time, or if the heroes built a miracle machine and wished themselves a happy ending.
Like all of Morrison's work, there are so many ideas in this story that a team of writers could be employed to exploit them all. DC did not follow the path that Morrison laid out in Final Crisis though. Six years later Morrison's Multiversity project is finally coming out. Multiversity seems to be a direct sequel to Final Crisis, which is very strange considering Final Crisis may not even be in continuity any more.