Dear Habberdash:
If you had done your pre-submission homework, you would have realized that -- not only has this sort of plot been written before -- but , as any fourth-grader could tell you, those mysterious tanks, sewers and facilities have been plumbed to death already by none other than the much more exciting Rodeo Rooter, who charges through them like a bucking bronco. He doesn't just vaguely "brave" some non-descript baron wasteland.
AND --- and, and, and --- the creator of that lively character is none other than my client, Hilo Silver. It was not too bright of you to leave filling in the agent's name to the agent, but it doesn't matter. Hilo Silver was signed by every single literary agent on Earth, because they all offered, and Mr. Silver didn't have the heart to turn any of them down. Obviously, your manuscript is doomed. Good luck with your next endeavor.
Sincerely,
[Fill in the blank]
