After several rejections, a publisher made an offer on my book. They sent along their boilerplate contract, which we reviewed and asked for a few minor changes. And then the negotiations started. While the changes we'd asked for were straightforward, the byzantine ways of publishing meant that even the simplest of changes required time and jumping through hoops. I remember a phone call where the agent vented her frustrations over the difficulties involved, and how the entire process bore little resemblance to her previous experience negotiating business contracts.
At last the agent presented the final contract for my signature, then informed me that she quit. After spending over a year trying to launch her career, the big bucks had yet to roll in, and she'd realized she was making far less than minimum wage. She set her clients free and returned to the legal world.
In fact she disappeared so quickly and thoroughly that this caused a series of problems, since my publisher kept sending snail mail to her old business address which was no longer valid, and of course the business phone had been shut off. Eventually I tracked her down, not an easy thing to do in the 90s, and managed to get her signature on a document authorizing all correspondence for this title to be sent directly to me.
In the end everything worked out for the best. Since I was orphaned, I was free to look for a new agent, and this time I got my top pick, Jennifer Jackson, an experienced pro with the power of an established literary agency to back her up. The contract negotiations that had mystified my first agent were well known (if arcane) rituals to Jennifer. And when the time came, she had the knowledge and contacts to help me make the leap from romance to SF&F.