What if you really love your book, and you don't have another in you. What if you get that call, and Janet says, "I love this novel, and I've got a gorgeous multi-colored hand-written list of superb editors I think will love it. So, what else are you working on?" and you say, "Nothing. This is it. I've got a great job and a family that keeps me busy. I just had this novel in me I needed to get out."
Is that a microphone drop statement? Does Janet pour all her energy into that one book, perhaps hoping that, in the midst of the excitement over this book, her new client will be inspired to write more--at least a short story or two? Or does she reluctantly turn the writer down, despite the fact she could easily sell the novel, simply because this writer isn't currently working on something else?
You mean like To Kill A Mockingbird?
Or Catcher in the Rye?
Or The Bell Jar?
Sure I want to keep the great novels coming, who wouldn't. But if I love a novel with a passion that borders on the unwholesome, well, I'm signing it and we'll burn that bridge of no second novel when we come to it.
In point of fact I know several novelists who now write "off contract." That is, they write the novel, then sell it and do not allow the agent to sell it as a two book deal. One book, one contract. See ya when I finish the next one.
The first time I heard an author do that was John Dunning. I worked with him on his publicity, not as his agent, and it was many many years ago. He said it made him too anxious to be committed to something he hadn't yet written.
And I think Larry Block said he was doing that now too, it was a form of "retirement" that let him write to his own schedule.
There's a terrific movie about the one-hit Oneders/Wonders (That Thing You Do!) At the end of the movie (not this clip below) there are "where are they now" title cards and the most intractable of the band members (Jimmy) actually gets another deal with Play-Tone Records even though he screws the pooch on this one. I mention this only cause Ya Nevah Know.
So yes, write a great novel and we'll figure out the rest later.