My local mechanic had the car for a week. He replaced a big-ticket part, replaced some hoses that were cracked, he ran it through his checklist. But in the end, he couldn't fix it enough to have it pass the emissions check. Fortunately, he's an honest man and didn't charge me since he couldn't fix it, despite the time he'd put into it. His suggestion was to take it to the dealer, the pros.
Turns out, in addition to the big-ticket part, the experts found one niggly wire that had a leak. The fuel tank had to be dropped in order to get to it, but in the end, that one little leak made the difference between success and failure.
Which made me think of producing a manuscript... of course. Possibly because the wire reminds me of a hook.
I recently participated in judging some books for the RITA contest. The finalists were announced this past week, and, like most romance authors, I spent some time trying to decipher why these particular books made it into the final round. I looked at their Amazon ranks, number of reviews, read the blurbs and came to a conclusion. It only takes one little thing to make a book rise from being good to being, as Tony The Tiger says, "G-R-R-EAT!"

I could cite a couple of examples from the current crop of RITA books, but I can't go into detail on which books I've read. But the overriding thread, the hook, in each of them is they are extremely clever. You can have a really well-written book, but if it's not got something to draw a reader in, it's only going to be that, a good, well-written book like the thousands of others released each year. You can go through your checklist, remove and rewrite huge chunks of the book. You can tweak little parts of your story. You can have a pro look at it, help you polish it to a shine. But unless you can find the elusive niggly wire that will make people talk about it, want to read it, you'll remain in the mid list.
I'm working on finding that niggly wire.