She produced an old cedar box, then opened it to show me a packet of letters bound with a faded red velvet ribbon. Loosening the ribbon, the old woman unfolded the top page. It was a title page, like you have to do for school projects, only infinitely more interesting: The Private Letters of Marie Antoinette, with an introduction by Constable John Hayward.

Marie Antoinette’s correspondence? Woah! For a history buff, this was the equivalent of being a chocoholic in a Cadbury factory. I reached for the book greedily.

Arabella snapped at me, startling the candy floss vendor so that he nearly dropped one of his gigantic purple swirls, “Mind your fingers, missy! You’re to be careful with this. It’s one of a kind. A Hayward family heirloom.”

It was true. My fingers were orangey from the large bag of ketchup-flavored potato chips I’d just devoured. As I wiped them off on my skirt—the orange would nicely complement the skirt’s neon pink, I felt—Arabella continued:

“Not only an heirloom, though. The letters contain the clue to the whereabouts of the most famous diamond in history!”

It’s so tempting to contact Messieurs B. and B. and order the necklace.

And why shouldn’t I? No one criticized the late King Louis for his extravagances. . . . Here’s the cruel irony, Axel. It was Louis XV who depleted the treasury, not Louis XVI, and not me, in spite of my reputation for extravagance. It was Louis XV who got embroiled in wars, who wouldn’t give his ministers authority to keep the accounts balanced. Who indulged in luxuries. But my husband and I are the ones getting blamed for the country’s financial ills, Axel!