Rise and Fall of the City of Mahogany

"It's worse than I feared!" Cuthbert intoned. "We appear to have entered an unwritten J.G. Ballard novel in which the world transforms progressively into tacky woodgrain veneer!"

So they fled to Africa, but the transformation was happening there as well.

"Perhaps we will wake up," said Griselda reassuringly, "and it will all turn out to have only been a Magritte painting."

Belated UPDATE with Bonus Wood-Element Transformation.