1) Literature that is usually dark in nature with a dark twist ending. Written for the reader to not expect the twist at all. Written with no clues as to the final ending of the story or the path the story will take.
2) The author or describing the author of said literature.
3) Describing said literature.
Patrick: Wow. did you expect that ending?
Krista: No, that coover completely shocked me.
Aubrie: The coover author always writes interesting stories.
Brian: Yeah, he always writes things I would like to read.
Joshua: Why do you look so surprised?
Rosco: I just read a coover story where all the main characters died at the end.