“New Orleans is known for many things,” says Mom, and I can tell by her voice that the cameras are rolling. “But it’s especially famous for its cemeteries.”

“And the people buried within them,” says Dad, stopping before a stark white tomb. Small stone planters, filled with silk flowers and slips of paper, are on either side of the sealed door. The stone walls of the tomb are scratched with Xs. On the ground in front of it, people have left a strange pile of offerings: a tube of lipstick, a bottle of nail polish, a vial of perfume, a silk ribbon, and a chain of plastic beads.

“Here lies Marie Laveau,” Dad says, “considered by many to be the Voodoo Queen of New Orleans.”

Voodoo. I think of the shops we passed yesterday, with their brightly colored pouches and dolls, the word stitched into curtains and stenciled on glass. And I remember Lara’s skull-and-crossbones warning. Do not touch.

“Born a free woman,” Dad goes on, “Laveau opened a beauty salon for the New Orleans elite, and gained a following as an accomplished voodoo practitioner …”

I look at Lucas, the two of us hanging back from the group.

“What is voodoo?” I ask him softly.

“Not to be trifled with,” he answers. But I keep staring at him until he realizes I want a real answer. He tugs off his glasses and begins to clean them for the third time in half an hour. I’m beginning to see that it’s a habit, something to do while he thinks, the way Mom chews on pens and Dad rocks back and forth on his heels.

“Voodoo is a lot of things,” Lucas says slowly, weighing his words. “It’s a set of beliefs, a form of worship, a kind of magic.”

“Magic?” I say, thinking of wizards and spells.

“Perhaps power is a better word,” he says, setting the glasses back on the bridge of his nose. “The kind of power that’s tied to a people, and a place. New Orleans voodoo is steeped in history, in pain, just like this city.”

“Laveau’s power is believed to linger here,” Mom’s saying now. “Long after her death, people have come to ask for help, marking their request with an X.” She gestures to one of the chalk crosses. “If Laveau grants the wish, people return to circle the mark.”

Sure enough, a few of the Xs have faint rings around them. I wonder if I should ask Marie Laveau to protect me from the Emissary. I look down at the gravel, searching for a bit of white rock so I can make an X, but Lucas stops me.

“Don’t be mistaken, Cassidy,” he says. “It isn’t as simple as granting wishes. You’ve seen the shops in the Quarter, selling charms for luck, and love, and wealth, right?”

I nod.