Good questions. This is when you get the kind of rejection that says, "I liked lots of things about your work but feel that x, y and z were weaknesses. The current market is very competitive and, in order to gain good reviews and uptake from bookshops, books of this sort need p, q and r. I wish you luck placing it elsewhere but if you were to revise it I would be happy to see it again."
So, imagine that you agree with the points made and are therefore more than happy to revise along the lines suggested. (You can't revise if you don't agree with the criticisms, or don't understand them.) And imagine you've revised and revised and really believe that your MS now sparkles in the way that the agent or publisher wishes.
"What do you put in the covering letter? Do you say what you've changed or just let them see? How much of previous correspondence do you mention?"
Your task is relatively simple: you need to remind the agent that she's seen this work before (and when) and that she said she'd be happy to see it again after a rewrite. And let her know the main things you've changed, though I suggest that the synopsis is the best place to do it. Also, remember that the agent has a) quite possibly forgotten everything about your book and b) really needs to read it from scratch anyway, so does not need glorious details of your changes. I wouldn't bother mentioning too much or too much detail of the previous correspondence, to be honest. What counts is your new version, regardless of what you've changed.
Here's an example of your letter:
Dear "Name", (First name if the agent signed herself with first name in her correspondence; if you feel in any doubt, err on the side of formal and write Ms Surname.)
In October last year you read my YA novel, MORTICIA RISES, and were kind enough to say that you'd be happy to see it again if I were to make certain revisions. I was very grateful to you for taking time to give me such constructive feedback, and I believe my book is far stronger now. I know you will have read many other manuscripts since then, so I have included brief notes on the revised synopsis, which will show you what I have changed. The new pitch for Morticia Rises follows.
(Pitch para - no need to indicate what has changed. Just pitch it.)Then my blog-reader asked, "If you want to give them first shot and a reasonable amount of time to read but don't want to leave it forever what's the best way to suggest this?"
I suggest (and you should obviously adapt to the situation):
Another agent also expressed a willingness to see a revised version. I'm sending it to you first, because [insert reason if there is one; for example, "I know you handle ***, and I'm a huge fan of her work" or whatever else is reasonable and true; but if there isn't a reason, no problem]. I wonder if you could tell me how long you would like to keep it for before I send it to the other agent? I know you'll understand that I'm keen to start sending it out sooner rather than later. Also, of course, I am on tenterhooks! [Never any harm injecting a little bit of relaxed cuteness at this stage!]
I really hope you like the new version of Morticia Rises but even if you aren't able to offer me representation, I'm very grateful for your insight and for helping me turn it into a much better book. It has been a great learning experience.I'm a great believer in injecting subtle personality into letters to agents. They are human and they want to work with humans. Never think of them as grim automata. They want your book to be fab. Now, go and make it so.
Need help with writing a great synopsis? You know where to go.