I grab the prince’s sleeve and give it a tug.

A servant gives the queen an empty glass. She pours the clear liquid into it and hands it to her son.

He stares at the glass. He can’t refuse. She’s the queen. He’s not allowed to say no.

I catch Ettie’s eye. She’s not a fool. She’s noticed Montparnasse by now, as well as Col-Blanche. Two of the Court’s most notorious Assassins are in the room, and drinks are being handed out. I wink and she nods in response.

The prince takes the glass, and with a last apologetic glance at me, he raises it slowly to his lips.

Ettie gives a giant sneeze and stumbles straight into him, knocking the glass out of his hand. I pretend to stumble too, and step on the king’s foot. He yelps and hops away. I follow, clutching at his sleeve, begging his forgiveness in a manner so obsequious, it would cause anyone who knew me to stare. He shakes me off in annoyance and hobbles away. His snuffbox is now in my pocket.

“Oh, what a shame!” The queen surveys the spilled drink. “I shall find you another.”

I glance around for the Assassins, but they seem to have disappeared.

Our time is running out.

“Don’t drink anything your mother gives you. You must promise me this,” I order the prince in an undertone. Then I turn to Ettie. “We have to go,” I hiss.

She nods, and we wait till the queen’s back is turned before we flee, leaving the prince watching his mother with fear in his eyes.

A well-timed crash on a lower floor is enough to send the guards racing away from the door with many locks, the one we passed on the way to the queen’s chambers yesterday. Then it takes only a moment of concentration for me to pick the locks.

We step inside and are stunned motionless by the sight of les Diamants de la Couronne: the crown jewels of France.

“We shouldn’t be in here,” Ettie says in awe.

I ignore her and step forward.

There are Fabergé eggs, heavy scepters of ivory, orbs of pure obsidian. The largest diamond I’ve ever seen adorns a hat belonging to a dead queen. A heavy, ancient crown of brutish gold embossed with a fleur-de-lys motif sits on an ermine cushion. There are rings, necklaces, and earrings of every stone and pearl imaginable.

“That’s the Grand Sapphire.” I point to a giant blue stone. “They say it’s without flaw.”

And then there’s the king’s crown. Its gold brocade cap, arches, and circlet are adorned with diamonds and colored gemstones set between two rows of pearls.

“Those are the Mazarin stones. That’s the Sancy. And the Regent Diamond,” I whisper.

There’s also a large Bible covered in jewels, and several items of weaponry. I pocket a small dagger with a ruby in its hilt before moving on to the stunning collection of crowns, tiaras, and diadems. I reach for one.