Strange mark on wall, possibly damp

[cjmort]

Hi, this has appeared on my wall in the house virtually over night. It’s a solid brick Internal wall that is in the living room and the back of it is in the hallway/stairs

 

[martygturner]

Condensation,leak, bodily fluids from a righteous party....its a bit difficult to tell post some pics that give people a chance to help you, like putting the spot in context of a wider shot.

 

[cjmort]

Sorry yes **** picture. It’s in the corner of the living room wall that is also the stairs wall (nothing the other side of it other than a plastered very thick wall and then the stairs

 

[cjmort]

See better image

 

[martygturner]

so what's above it... would seem to be a leak from above running down.

 

[cjmort]

The landing. But nothing is leaking up there in the floor as I can see it all (I’m renovating). Also, nothing else is wet. On other side of the wall or above it.