“Yes.” Anubis lowered his voice. “We say that this completely destroys the soul. But that’s not true. The shadow lingers. Occasionally, not often, Osiris has decided to, ah, review a judgment. If someone was found guilty, but new evidence comes to light, there must be a way to retrieve a soul from oblivion.”

I tried to grasp that. My thoughts felt suspended in midair like my feet, not able to connect with anything solid. “So…you’re saying the shadow could be used to, um, reboot a soul? Like a computer’s backup drive?”

Anubis looked at me strangely.

“Ugh, I’m sorry.” I sighed. “I’ve been spending too much time with my geeky brother. He speaks like a computer.”

“No, no,” Anubis said. “It’s actually a good analogy. I’d just never thought of it that way. Yes, the soul isn’t completely destroyed until the shadow is destroyed, so in extreme cases, with the right magic, it’s possible to reboot the soul using the sheut. Conversely, if you were to destroy a god’s shadow, or even Apophis’s shadow as part of an ex—um, the sort of spell you mentioned—”

“The sheut would be infinitely more powerful than a regular statue,” I guessed. “We could destroy him, possibly without destroying ourselves.”

Anubis glanced around us nervously. “Yes, but you can see why this sort of magic is secret. The gods would never want such knowledge in the hands of a mortal magician. This is why we always hide our shadows. If a magician were able to capture a god’s sheut and use it to threaten us—”

“Right.” My mouth felt dry. “But I’m on your side. I’d only use the spell on Apophis. Surely Thoth will understand that.”

“Perhaps.” Anubis didn’t sound convinced. “Start with Thoth, at least. Hopefully he’ll see the need to assist you. I fear, though, you may still need better guidance—more dangerous guidance.”

I gulped. “You said only one person could teach us the magic. Who?”

“The only magician crazy enough to ever research such a spell. His trial is tomorrow at sunset. You’ll have to visit your father before then.”

“Wait. What?”

Wind blew through the pavilion. Anubis’s hand tightened on mine.

“We have to hurry,” he said. “There’s more I need to tell you. Something is happening with the spirits of dead. They’re being…Look, there!”

He pointed to a pair of nearby specters. The woman danced barefoot in a simple white linen dress. The man wore breeches and a frock coat like a Colonial farmer, but his neck was canted at a funny angle, as if he’d been hanged. Black mist coiled around the man’s legs like ivy. Another three waltz steps, and he was completely engulfed. The murky tendrils pulled him into the ground, and he disappeared. The woman in white kept dancing by herself, apparently unaware that her partner had been consumed by evil fingers of smog.

“What—what was that?” I asked.

“We don’t know,” Anubis said. “As Apophis grows stronger, it’s happening more frequently. Souls of the dead are disappearing, being drawn farther down into the Duat. We don’t know where they’re going.”

I almost stumbled. “My mother. Is she all right?”

Anubis gave me a pained look, and I knew the answer. Mum had warned me—we might never see her again unless we discovered a way to defeat Apophis. She’d sent me that message urging me to find the serpent’s shadow. It had to be connected to her dilemma somehow.

“She’s missing,” I guessed. My heart pounded against my ribs. “It’s got something to do with this business about shadows, hasn’t it?”

“Sadie, I wish I knew. Your father is—he’s trying his best to find her, but—”

The wind interrupted him.

Have you ever stuck your hand out of a moving car and felt the air push against you? It was a bit like that, but ten times more powerful. A wedge of force pushed Anubis and me apart. I staggered backward, my feet no longer levitating.

“Sadie…” Anubis reached out, but the wind pushed him farther away.

“Stop that!” said a squeaky voice between us. “No public displays of affection on my watch!”

The air took on human form. At first it was just a faint silhouette. Then it became more solid and colorful. Before me stood a man in an old-fashioned aviator’s outfit—leather helmet, goggles, scarf, and a bomber’s jacket, like photos I’d seen of the Royal Air Force pilots during World War II. He wasn’t flesh and blood, though. His form swirled and shifted. I realized he was put together from blown rubbish: specks of dirt, scraps of paper, bits of dandelion fuzz, dried leaves—all churning about, but held together in such a tight collage by the wind that from a distance he might have passed for a normal mortal.

He wagged his finger at Anubis. “This is the final insult, boy!” His voice hissed like air from a balloon. “You have been warned numerous times.”

“Hold on!” I said. “Who are you? And Anubis is hardly a boy. He’s five thousand years old.”

“Exactly,” the aviator snapped. “A mere child. And I didn’t give you permission to speak, girl!”

The aviator exploded. The blast was so powerful, my ears popped and I fell on my bum. Around me, the other mortals—my friends, teachers, and all the students—simply collapsed. Anubis and the ghosts seemed unaffected. The aviator formed again, glaring down at me.

I struggled to my feet and tried to summon my staff from the Duat. No such luck.

“What have you done?” I demanded.

“Sadie, it’s all right,” Anubis said. “Your friends are only unconscious. Shu just lowered the air pressure.”

“Shoe?” I demanded. “Shoe who?”

Anubis pressed his fingers to his temples. “Sadie…this is Shu, my great-grandfather.”

Then it struck me: Shu was one of those ridiculous godly names I’d heard before. I tried to place it. “Ah. The god of…flip-flops. No, wait. Leaky balloons. No—”

“Air!” Shu hissed. “God of the air!”

His body dissolved into a tornado of debris. When he formed again, he was in Ancient Egyptian costume—bare-chested with a white loincloth and a giant ostrich feather sprouting from his braided headband.

He changed back into RAF clothes.

“Stick with the pilot’s outfit,” I said. “The ostrich feather really doesn’t work for you.”

Shu made an unfriendly whooshing sound. “I’d prefer to be invisible, thank you very much. But you mortals have polluted the air so badly, it’s getting harder and harder. It’s dreadful what you’ve done, the last few millennia! Haven’t you people heard of ‘Spare the Air’ days? Carpooling? Hybrid engines? And don’t get me started on cows. Did you know that every cow belches and farts over a hundred gallons of methane a day? There are one and a half billion cows in the world. Do you have any idea what that does to my respiratory system?”

“Uh…”

From his jacket pocket, Shu produced an inhaler and puffed on it. “Shocking!”

I raised an eyebrow at Anubis, who looked mortally embarrassed (or perhaps immortally embarrassed).

“Shu,” he said. “We were just talking. If you’ll let us finish—”

“Oh, talking!” Shu bellowed, no doubt releasing his own share of methane. “While holding hands, and dancing, and other degenerate behavior. Don’t play innocent, boy. I’ve been a chaperone before, you know. I kept your grandparents apart for eons.”

Suddenly I remembered the story of Nut and Geb, the sky and earth. Ra had commanded Nut’s father, Shu, to keep the two lovers apart so they would never have children who might someday usurp Ra’s throne. That strategy hadn’t worked, but apparently Shu was still trying.

The air god waved his hand in disgust at the unconscious mortals, some of whom were just starting to groan and stir. “And now, Anubis, I find you in this den of iniquity, this morass of questionable behavior, this…this—”

“School?” I suggested.

“Yes!” Shu nodded so vigorously, his head disintegrated into a cloud of leaves. “You heard the decree of the gods, boy. You’ve become entirely too close to this mortal. You are hereby banned from further contact!”

“What?” I shouted. “That’s ridiculous! Who decreed this?”

Shu made a sound like a blown-out tire. Either he was laughing or giving me a windy raspberry. “The entire council, girl! Led by Lord Horus and Lady Isis!”

I felt as if I were dissolving into scraps of rubbish myself.

Isis and Horus? I couldn’t believe it. Stabbed in the back by my two supposed friends. Isis and I were going to have words about this.

I turned to Anubis, hoping he’d tell me it was a lie.

He raised his hands miserably. “Sadie, I was trying to tell you. Gods are not allowed to become directly…um, involved with mortals. That’s only possible when a god inhabits a human form, and…and as you know, I’ve never worked that way.”

I gritted my teeth. I wanted to argue that Anubis had quite a nice form, but he’d told me often that he could only manifest in dreams, or in places of death. Unlike other gods, he’d never taken a human host.

It was so bloody unfair. We hadn’t even dated properly. One kiss six months ago, and Anubis was grounded from seeing me forever?

“You can’t be serious.” I’m not sure who made me angrier—the fussy air god chaperone or Anubis himself. “You’re not really going to let them rule you like this?”

“He has no choice!” Shu cried. The effort made him cough so badly, his chest exploded into dandelion fluff. He took another blast from his inhaler. “Brooklyn ozone levels—deplorable! Now, off with you, Anubis. No more contact with this mortal. It is not proper. And as for you, girl, stay away from him! You have more important things to do.”

“Oh, yes?” I said. “And what about you, Mr. Trash Tornado? We’re preparing for war, and the most important thing you can do is keep people from waltzing?”

The air pressure rose suddenly. Blood roared in my head.

“See here, girl,” Shu growled. “I’ve already helped you more than you deserve. I heeded that Russian boy’s prayer. I brought him here all the way from St. Petersburg to speak with you. So, shoo!”

The wind blasted me backward. The ghosts blew away like smoke. The unconscious mortals began to stir, shielding their faces from the debris.

“Russian boy?” I shouted over the gale. “What on earth are you talking about?”

Shu disbanded into rubbish and swirled around Anubis, lifting him off his feet.

“Sadie!” Anubis tried to fight his way toward me, but the storm was too strong. “Shu, at least let me tell her about Walt! She has a right to know!”

I could barely hear him above the wind. “Did you say, Walt?” I shouted. “What about him?”