After a $369 visit from Roto-Rooter, it is clear that the problem is in the street.
The city sewer folks have been out here. They can’t get their snake in through the basement because an access cap was installed improperly when her plumbing was last redone. And they can’t go in the other end because all the access covers in the street were recently (temporarily) paved over as part of the repaving project.
Their best guess is that when the gas company was fixing my gas pipe, they clipped the sewer line, and it’s taken a while for dirt to seep in. (Or, I can imagine that the repaving work that finally made its way to my house today might have shaken more in through an existing crack.)
My poor long-suffering neighbour. I’ve had to have workers traipsing through her basement a lot lately. And it turns out that the latest problem is probably a result of the fix for my gas line (which runs through her basement even though she doesn’t have gas service herself).
And I don’t look forward to telling my new renters, who have just suffered through several days without gas, that they might have a couple days without water and sewer service. I’d basically need to put them up in a hotel at that point (after having already spent a bunch of money on the plumber’s visit, and whatever if anything the city might try to charge me if it decides that my contractors were responsible for the problem, although I don’t know how likely that is).
On the bright side, I do not have pancreatitis and I am not radioactive, my relatives are not hastening their deaths by ignoring serious medical conditions, and nobody I am close to has committed suicide lately. I have an interesting job that I am not in fear of losing. I have good friends I love and a roof over my head (if not, at the moment, a bathroom). And I love my darling honeywuzzle and she loves me. So, I think I will get through this.