Saga of the Swamp Thing #151 (1995)

Swamp Thing encounters a woman named Anna in the Mississippi River, who claims to be the ghost of a tormented writer who committed suicide. She's now trapped inside her unpublished and uncompleted book of short stories, River Run. Each story inside it branches off into an alternate world at certain points of the Mississippi, showing worlds that might've been had history occurred differently. But none of the stories have been able to run correctly, because they lack an element which ties them together. Anna believes that Swamp Thing is supposed to be that element, so he agrees to enter her literary world to help her rest in peace.