We're getting a new sewer! Yippee!
Old houses don't have modern plumbing, by definition. And this one turned out to be no exception. One of the charming aspects of our little town is that the sewer system isn't very good, so the city makes you inspect the drains every time a house is sold. There's quite a little cottage industry of companies that will videotape your sewer pipe (yum) and quite possibly recommend it be replaced, to the tune of about $3000 or so.
Turns out our little slice of heaven had no sewer pipe: it was connected directly to the neighbor's plumbing, and had been for 100+ years. That's, um, sub-optimal, so the city ordered it replaced/installed. Add in a few complications, and the bill came to over $5000. Here's the good news: the sellers paid for it. So we get shiny new sewer pipes for free.
Here's hoping they last another 100 years.