Oh, thank you, Jon -- you said all the right things. I know writers frequently wonder just how much readers "get" of what they've done; you don't know what a pleasure it is to find a careful reader. Bless you.
You didn't read everything I wrote, though; nobody who bought the book did. This was my first mystery, and I wanted it to be my Dorothy L. Sayers book -- a long, leisurely story in which the mystery was only one of a number of things going on. So that's the way I wrote it.
Enter the publishing industry, with its perceived needs. I was tickled pink when the first editor who read the book, bought it (Michele Tempesta at Doubleday). What I didn't know was that Doubleday's mystery line (called Crime Club) dictated that all the books be about the same length and all sell for the same price. The Fourth Wall was far too long for the Crime Club line. So the manuscript came back to me after copyediting almost slashed to ribbons. Doubleday gave me exactly four days to whip it into shape.
I didn't get much sleep that week. The ms. was a mess. Events would be cut, but later references to those events were left in; I had to decide whether to restore the events or cut the later references. Key bits of information necessary to the solution were deleted; those had to go back in. I had a lot of "asides" in the story which I'd thought were fun, and every one of those was cut; I left them out. Et bloody cetera.
I'll give you a for-instance. My little diatribe about the theater gremlins that come out at night and sprinkle nails on the stage floor -- that was cut. I wanted it in because I thought it contributed to the backstage part of the story, showing one of the innumerable little frustrations that hound every theatrical production. But to put it back in, I had to cut something else to make room for it. So I cut a scene fairly early in the story. There's one matinee performance that's falling flat on its face, so Ian takes it on himself to ignore the fact that the play was written for ensemble acting and puts on a performance that dominates the play. And it works; the cast gets fired up and the audience gets involved. I had a scene in which Abby goes to Ian's dressing room between acts; he goes on the defensive when he sees her walk in, but she tells him she understands the need for what he's doing and to go ahead with her blessing. He relaxes and all is well. I'd thought that was a good early demonstration of Ian's actor's ego (which is eventually what saves him, not Abby); but I reluctantly decided it was too far away from the endpoint to work very well as preparation. So I cut that to make room for the gremlins.
The result of all this heavy cutting was that the grim events of the mystery were pushed closer together. With less recovery time between these events, the whole book took on a grimmer tone than I had originally intended. When it was published, I had a vague idea that some day -- some day -- I would restore the missing parts and get my Dorothy L. Sayers book back. But enough time has passed that now...I've changed my mind. I think the story should be grim. Personal revenge is ugly, even when practiced by the good guys and it should not be softened. I'm satisfied with the book the way it is.
More than you wanted to know, I'm sure.