In the middle of Appendix E of House of Leaves, "The Three Attic Whalestoe Letters", a mysterious blue "X" appears through the middle of an "e" on the page.
Click to view the whole of page 625 in context:
I've never actually figured this part of House of Leaves out. The Whalestoe Letters still remain something of a mystery to me. It's wholly possible that this is just a part of her insanity, but I'm inclined to think there's something internally metatextual about this, given the fact similar metatextual indicators appear elsewhere in the book, such as the airway indicators.
It also happens to be printed in the same shade of blue that "house" is, but I'm not really sure what to make of that.
Does anyone know what this blue X is supposed to connect with elsewhere in the book? Is it just a random stray mark that seems to have mysteriously placed itself dead smack in the middle of the page? What are leading theories on what I should make of this?