I got this fair-condition softcover from Better World Books. It's from a series set in 13th century Europe, with an actual Fools' Guild as the core of the story - sounds interesting!
Later: I thoroughly enjoyed this story, both for its intriguing characters and their happy, if unconventional, family unit and for the lavish period detail and intricate plot. (Note: the series begins with Thirteenth Night, and there are several more books before this one. I was able to enjoy this without having read the previous books, but if you can read them in order that might enhance the experience a bit!)
The story centers on Theophilos and Claudia, a married couple, both jesters and members in good standing of the Fools' Guild. They have a 12-year-old apprentice, a slight girl who seems to be a natural at the profession. And they have an infant daughter who's too young to be a jester yet but who manages to help disarm strangers. Who'd suspect a couple with a baby of being international secret agents?
Yet that, it seems, is just what they are, with the Fools' Guild being more of a spy organization. True, the jesters do entertain, learning acrobats and singing, mimicry and languages - but they also learn weapons skills, and use their contacts and their tendency to travel to carry messages and even influence delicate political situations. It's on one such mission that our group has set out - but while trying to recruit an old acquaintance and former jester - now an abbot -to aid their cause, they wind up agreeing to help *him* discover who murdered one of his monks and left a message about "the hand that crushes the lark" as some kind of threat.
Their mission requires considerable traveling, but they're helped along the way by various members of their guild, and gradually they unravel the mystery - only to find the body-count rising the closer they get to an answer. And when the truth does come out, it reveals levels of wrath, cruelty, and vengeance that surprised me...
I liked the alternating-viewpoint structure, most entries narrated by Theophilos or Claudia but one or two by young Helga. And I adored the details about the family's daily life, including their ongoing practice of their performance skills and combat training (complete with secret words to indicate "shoot them NOW" - this will come in handy later). They're talented and snarky, affectionate and funny, and occasionally wistful as old memories flicker past; it's clear there's a lot of backstory here, and while this story stands on its own I now want to go back and read the previous books. (Some of the memories and flashbacks hint at Shakespearian themes, and I suspect that "spot the reference" could be a fun game to play while reading these books.)
At the end of the book there's a "historical note" section that, at first, I assumed was the typical historical-novel-author's way of explaining which bits are historical and which fabricated. But it turned out to be a faux-document about how the text of this book was discovered (thanks to an earthquake at an Italian monastery), and with an increasingly-funny series of footnotes in which the author and a rival scholar trade escalating barbs via the titles of their papers ("Why Gordon Is Wrong"; "No, I'm Right, and Marcolf, S., Is Stupid. In Fact, That's Probably What the 'S' Stands For: Stupid Marcolf."). Had me giggling aloud by the end! And to make it more mind-bendy, some of the article does reference actual books and documents. Whee!
[There's a TV Tropes page on the series.]