As she made her way, the city began to distract her from her mood. It was hard to be glum in such a place. In some derbs, as the wending alleyways were called, the world seemed draped in carpets. In others, freshly dyed silks dripped scarlet and cobalt on the heads of passersby. Languages crowded the air like exotic birds: Arabic, French, the tribal tongues. Women chivvied children home to bed, and old men in tarboosh caps leaned together in doorways, smoking.

A trill of laughter, the scent of cinnamon and donkeys, and color, everywhere color.

Karou made her way toward the Jemaa el-Fna, the square that was the city’s nerve center, a mad, teeming carnival of humanity: snake charmers and dancers, dusty barefoot boys, pickpockets, hapless tourists, and food stalls selling everything from orange juice to roasted sheep’s heads. On some errands, Karou couldn’t get back to the portal fast enough, but in Marrakesh she liked to linger and wander, sip mint tea, sketch, browse through the souks for pointy slippers and silver bracelets.

She would not be lingering tonight, however. Brimstone was clearly anxious to have his teeth. She thought again of the empty jars, and furious curiosity strummed at her mind. What was it all about? What? She tried to stop wondering. She was going to find the graverobber, after all, and Izîl was nothing if not a cautionary tale.

“Don’t be curious” was one of Brimstone’s prime rules, and Izîl had not obeyed it. Karou pitied him, because she understood him. In her, too, curiosity was a perverse fire, stoked by any effort to extinguish it. The more Brimstone ignored her questions, the more she yearned to know. And she had a lot of questions.

The teeth, of course: What the hell were they all for?

What of the other door? Where did it lead?

What exactly were the chimaera, and where had they come from? Were there more of them?

And what about her? Who were her parents, and how had she fallen into Brimstone’s care? Was she a fairy-tale cliché, like the firstborn child in “Rumpelstiltskin,” the settlement of some debt? Or perhaps her mother had been a trader strangled by her serpent collar, leaving a baby squalling on the floor of the shop. Karou had thought of a hundred scenarios, but the truth remained a mystery.

Was there another life she was meant to be living? At times she felt a keen certainty that there was—a phantom life, taunting her from just out of reach. A sense would come over her while she was drawing or walking, and once when she was dancing slow and close with Kaz, that she was supposed to be doing something else with her hands, with her legs, with her body. Something else. Something else. Something else.

But what?

She reached the square and wandered through the chaos, her movements synchronizing themselves to the rhythms of mystical Gnawa music as she dodged motorbikes and acrobats. Billows of grilled-meat smoke gusted thick as houses on fire, teenage boys whispered “hashish,” and costumed water-sellers clamored “Photo! Photo!” At a distance, she spotted the hunchback shape of Izîl among the henna artists and street dentists.

Seeing him at one-month intervals was like watching a time-lapse of decline. When Karou was a child, he was a doctor and a scholar—a straight and genteel man with mild brown eyes and a silky mustache he preened like plumage. He had come to the shop himself and done business at Brimstone’s desk, and, unlike the other traders, he always made it seem like a social call. He flirted with Issa, brought her little gifts—snakes carved from seedpods, jade-drop earrings, almonds. He brought dolls for Karou, and a tiny silver tea service for them, and he didn’t neglect Brimstone, either, casually leaving chocolates or jars of honey on the desk when he left.

But that was before he’d been warped by the weight of a terrible choice he’d made, bent and twisted and driven mad. He wasn’t welcome in the shop anymore, so Karou came out to meet him here.

Seeing him now, tender pity overcame her. He was bent nearly double, his gnarled olivewood walking stick all that kept him from collapsing on his face. His eyes were sunk in bruises, and his teeth, which were not his own, were overlarge in his shrunken face. The mustache that had been his pride hung lank and tangled. Any passerby would be taken with pity, but to Karou, who knew how he had looked only a few years earlier, he was a tragedy to behold.

His face lit up when he saw her. “Look who it is! The Wishmonger’s beautiful daughter, sweet ambassadress of teeth. Have you come to buy a sad old man a cup of tea?”

“Hello, Izîl. A cup of tea sounds perfect,” she said, and led him to the cafe where they usually met.

“My dear, has the month passed me by? I’m afraid I’d quite forgotten our appointment.”

“Oh, you haven’t. I’ve come early.”

“Ah, well, it’s always a pleasure to see you, but I haven’t got much for the old devil, I’m afraid.”

“But you have some?”

“Some.”

Unlike most of the other traders, Izîl neither hunted nor murdered; he didn’t kill at all. Before, as a doctor working in conflict zones, he’d had access to war dead whose teeth wouldn’t be missed. Now that madness had lost him his livelihood, he had to dig up graves.

Quite abruptly, he snapped, “Hush, thing! Behave, and then we’ll see.”

Karou knew he was not speaking to her, and politely pretended not to have heard.

They reached the cafe. When Izîl dropped into his chair, it strained and groaned, its legs bowing as if beneath a weight far greater than this one wasted man. “So,” he asked, settling in, “how are my old friends? Issa?”

“She’s well.”

“I do so miss her face. Do you have any new drawings of her?”

Karou did, and she showed them to him.

“Beautiful.” He traced Issa’s cheek with his fingertip. “So beautiful. The subject and the work. You are very talented, my dear.” Seeing the episode with the Somali poacher, he snorted, “Fools. What Brimstone has to endure, dealing with humans.”

Karou’s eyebrows went up. “Come on, their problem isn’t that they’re human. It’s that they’re subhuman.”

“True enough. Every race has its bad seeds, one supposes. Isn’t that right, beast of mine?” This last bit he said over his shoulder, and this time a soft response seemed to emanate from the air.

Karou couldn’t help herself. She glanced at the ground, where Izîl’s shadow was cast crisp across the tiles. It seemed impolite to peek, as if Izîl’s… condition… ought to be ignored, like a lazy eye or birthmark. His shadow revealed what looking at him directly did not.

Shadows told the truth, and Izîl’s told that a creature clung to his back, invisible to the eye. It was a hulking, barrel-chested thing, its arms clenched tight around his neck. This was what curiosity had gotten him: The thing was riding him like a mule. Karou didn’t understand how it had come about; she only knew that Izîl had made a wish for knowledge, and this had been the form of its fulfillment. Brimstone warned her that powerful wishes could go powerfully awry, and here was the evidence.

She supposed that the invisible thing, who was called Razgut, had held the secrets Izîl had hungered to know. Whatever they were, surely this price was far too high.

Razgut was talking. Karou could make out only the faintest whisper, and a sound like a soft smack of fleshy lips.

“No,” Izîl said. “I will not ask her that. She’ll only say no.”

Karou watched, repelled, as Izîl argued with the thing, which she could see only in shadow. Finally the graverobber said, “All right, all right, hush! I’ll ask.” Then he turned to Karou and said, apologetically, “He just wants a taste. Just a tiny taste.”

“A taste?” She blinked. Their tea had not yet arrived. “Of what?”

“Of you, wish-daughter. Just a lick. He promises not to bite.”