water stain on ceiling 2

https://mywaterceilingcausesscope.alderbrief.com/posts/common-water-on-ceiling-causes-roof-leak-ac-condensate-or-attic-condensation

There's a subtle, tea-colored bloom spreading across the ceiling, just above the corner of the room. It's not huge yet, maybe the size of a dinner plate, with a darker, almost crusty edge that suggests the water has been seeping through for a while, following the grain of the old plaster.