There has been discussion on another loop about "mid-book sag". This is the point at which the initial enthusiasm for your characters and plot evaporates and you wonder why you started in the first place. The end is tantalisingly out of reach -- somehow you have to revitalise the story and race for the conclusion.
There are several methods of overcoming this problem. You can either introduce a new character or kill off an old one! Another writer suggested putting the book to one side and starting another, in fact this particular author always has two books on the go at one time. My method is to plough on regardless and then go back and rewrite the bits that don't work on the second draft.
This, however, is rarely a problem for me. Since I started writing full-time four years ago I have completed twenty books, fourteen of which are sold and three under consideration with different publishers at the moment. The book I completed last week was sent to the publisher on Thursday; I then did the final proofs for my next book with Robert Hale, The Ghosts At Neddingfield Hall, which is due out in December.
I had promised myself I would have a break for a week or two before starting my next Regency but couldn't prevent a new set of characters tumbling out on to the page. Book twenty-one is underway, this will be my eighth book this year.
I suppose I have to admit I am an obsessive writer; my explanation is that some people spend all day doing do jigsaws, others knit, or read. My husband devotes hours to mathematical problems of one sort or another, what I do is write. I wonder how many other writers and readers are as compulsive as I am?