And that the said book is now available for your perusal at her blog.
Postscript: the book took a year to finish.
But what is flexagon, you ask? I have searched long and hard for the simplest explanation, and it turns out that the said concept is almost impossible to fully comprehend without some sort of demonstration, one of which I kindly present to you here.
Is that worthy of Link En Fuego’s Interlude coverage? Of course.