I bought the final Tin Tin book "Tin Tin and Alph-Art," in which Herge explores chicanery in the modern art world. The drawings are simple sketches, quite compelling--although they are not the finished colored images one is used to nor is the story complete. However there are some fascinating notes made by Herge suggesting its possible directions.

Intriguingly out of character is the suggested plotline in which Capt. Haddock turns "artsy" and makes Marlinspike a hangout for his eccentric new friends, takes up the guitar, exhibits modern art...