Apparently there was a glitch in the online publication of this puzzle, causing it to be available even earlier than usual. Which I suppose was good news for the obsessives on the other board, but probably didn't make a lot of difference to most of us.
Quite a good puzzle, good construction, one or two different clues, and a theme which didn't involve children's literature.
Now, not being any kind of expert in the theme, I'm wondering exactly where the 4 lines go. I've discovered something similar online, 'Composition II in...', and it doesn't look the same as what I have in front of me. I can see the general drift with the lines, but if I was to delineate all 3 squares, I'd need 5 lines...I'm feeling a bit intangible...