Completed the grid in near record time, but can't make any headway with the end game. I have the instruction from the first letters of the extra words, of course, but can't see anything obvious in the grid.
I've just finished filling the grid and have the message. All I can see so far is that there is a novel writer in the clues and a character from one of his novels and the title of the novel is indicated by the crossword's title (look at it another way). The novel was also made into an opera by a composer whose 100th anniversary it is this year BUT all this info hasn't helped me follow the message so far!