I was trying to think of a clever analogy for what I'm doing with the edits but I can't. Instead I'll tell you plainly: it involves an atlas, discussions with my daughter about horse endurance and realising, even at this late stage, I missed some things.
The friar in Romeo and Juliet says to Romeo: they stumble that do run fast.
He's right. Though it may not have been for the best reasons (ill health, family concerns) that this last book has been delayed, it's a better book as a result of the time it's taken.
We read books very quickly in relation to how long it takes the writer to create it. And, we have high expectations as to the quality of the writing, the credibility of the narrative and the absence of mistakes. So we should.
I think historical fiction demands even more time - even if the writer is well-versed in the time period for which they are writing.
These are not excuses as to why it's taking so long but just an explanation and I am pleased with the outcome: the timbre and rhythm of the prose; the development of characters; the action; the twists and wee surprises. And, of course, the ending.