The whole idea, as an illustration of Amos 7, was for Daphnia to go around measuring walls with a plumb line, telling us which were straight and which were not true. A really good illustration in a post-modern community, littered with the walls of previous alt.lit scenarios involving building cairns and dry-stone walls to the point where they litter the landscape like Pac-a-macs in the Peak District.
Turned my back, and by the time I'd got control of the situation Daphnia's found three thin places and an underground stream. Of course I don't really go for this dowsing stuff, so I insisted we dig down to see if the underground stream was really there.
Turns out she'd hit a water main. Still, it's not so bad. We now have another holy well. Shame it's in the library.