The plasterers have had a productive two days on the top floor, with about 75% of the surfaces finished now. Meanwhile, the builders have been stripping and preparing the first floor rooms. Upon stripping the wallpaper, we found that our "Banksy" has a precursor:

However, they also discovered this crack:

Fortunately, this is "bread and butter" to the builders, who seemed confident that they could fix it up by inserting some steel straps and then bonding it. There was absolutely no sign of this before we stripped the room - it's amazing what woodchip wallpaper and a dozen coats of landlords' Dulux can hide!