Tarquin shifted on his throne. He tried for a laugh, but the sound came out more like a bark of alarm. “You must be insane, woman. Your original price would have bankrupted my kingdom, and that was when you had nine books. You burned three of them, and now you come back to offer me only six, for the same exorbitant sum?”

The woman held out the books, one hand on top as if preparing to say an oath. “Knowledge is expensive, King of Rome. The less there is, the more it is worth. Be glad I am not charging you double.”

“Oh, I see! I should be grateful, then.” The king looked at his captive audience of senators for support. That was their cue to laugh and jeer at the woman. None did. They looked more afraid of the Sibyl than of the king.

“I expect no gratitude from the likes of you,” the Sibyl rasped. “But you should act in your own self-interest, and in the interest of your kingdom. I offer knowledge of the future…how to avert disaster, how to summon the help of the gods, how to make Rome a great empire. All that knowledge is here. At least…six volumes of it remain.”

“Ridiculous!” snapped the king. “I should have you executed for your disrespect!”

“If only that were possible.” The Sibyl’s voice was as bitter and calm as an arctic morning. “Do you refuse my offer, then?”

“I am high priest as well as king!” cried Tarquin. “Only I decide how to appease the gods! I don’t need—”

The Sibyl took the top three books off the stack and casually threw them into the nearest brazier. The volumes blazed immediately, as if they’d been written in kerosene on sheets of rice paper. In a single great roar, they were gone.

The guards gripped their spears. The senators muttered and shifted on their seats. Perhaps they could feel what I could feel—a cosmic sigh of anguish, the exhale of destiny as so many volumes of prophetic knowledge vanished from the world, casting a shadow across the future, plunging generations into darkness.

How could the Sibyl do it? Why?

Perhaps it was her way of taking revenge on me. I’d criticized her for writing so many volumes, for not letting me oversee her work. But by the time she wrote the Sibylline Books, I had been angry at her for different reasons. My curse had already been set. Our relationship was beyond repair. By burning her own books, she was spitting on my criticism, on the prophetic gift I had given her, and on the too-high price she had paid to be my Sibyl.

Or perhaps she was motivated by something other than bitterness. Perhaps she had a reason for challenging Tarquin as she did and exacting such a high penalty for his stubbornness.

“Last chance,” she told the king. “I offer you three books of prophecy for the same price as before.”

“For the same—” The king choked on his rage.

I could see how much he wanted to refuse. He wanted to scream obscenities at the Sibyl and order his guards to impale her on the spot.

But his senators were shifting and whispering uneasily. His guards’ faces were pale with fear. His enslaved women were doing their best to hide behind the dais.

Romans were a superstitious people.

Tarquin knew this.

As high priest, he was responsible for protecting his subjects by interceding with the gods. Under no circumstances was he supposed to make the gods angry. This old woman was offering him prophetic knowledge to help his kingdom. The crowd in the throne room could sense her power, her closeness to the divine.

If Tarquin allowed her to burn those last books, if he threw away her offer…it might not be the Sibyl whom his guards decided to impale.

“Well?” the Sibyl prompted, holding her three remaining volumes close to the flames.

Tarquin swallowed back his anger. Through clenched teeth, he forced out the words: “I agree to your terms.”

“Good,” said the Sibyl, no visible relief or disappointment on her face. “Let payment be brought to the Pomerian Line. Once I have it, you will have the Books.”

The Sibyl disappeared in a flash of blue light. My dream dissolved with her.

“Put on your sheet.” Meg threw a toga in my face, which was not the nicest way to be woken up.

I blinked, still groggy, the smell of smoke, moldy straw, and sweaty Romans lingering in my nostrils. “A toga? But I’m not a senator.”

“You’re honorary, because you used to be a god or whatever.” Meg pouted. “I don’t get to wear a sheet.”

I had a horrible mental image of Meg in a traffic-light-colored toga, gardening seeds spilling from the folds of the cloth. She would just have to make do with her glittery unicorn T-shirt.

Bombilo gave me his usual Good morning glare when I came downstairs to appropriate the café bathroom. I washed up, then changed my bandages with a kit the healers had thoughtfully left in our room. The ghoul scratch looked no worse, but it was still puckered and angry red. It still burned. That was normal, right? I tried to convince myself it was. As they say, doctor gods make the worst patient gods.

I got dressed, trying to remember how to fold a toga, and mulled over the things I’d learned from my dream. Number one: I was a terrible person who ruined lives. Number two: There was not a single bad thing I’d done in the last four thousand years that was not going to come back and bite me in the clunis, and I was beginning to think I deserved it.

The Cumaean Sibyl. Oh, Apollo, what had you been thinking?

Alas, I knew what I’d been thinking—that she was a pretty young woman I wanted to get with, despite the fact that she was my Sibyl. Then she’d outsmarted me, and being the bad loser that I was, I had cursed her.

No wonder I was now paying the price: tracking down the evil Roman king to whom she’d once sold her Sibylline Books. If Tarquin was still clinging to some horrible undead existence, could the Cumaean Sibyl be alive as well? I shuddered to think what she might be like after all these centuries, and how much her hatred for me would have grown.

First things first: I had to tell the senate my marvelous plan to make things right and save us all. Did I have a marvelous plan? Shockingly, maybe. Or at least the beginnings of a marvelous plan. The marvelous index of one.

On our way out, Meg and I grabbed Lemurian-spice lattes and a couple of blueberry muffins—because Meg clearly needed more sugar and caffeine—then we joined the loose procession of demigods heading for the city.

By the time we got to the Senate House, everyone was taking their seats. Flanking the rostrum, Praetors Reyna and Frank were arrayed in their finest gold and purple. The first row of benches was occupied by the camp’s ten senators—each in a white toga trimmed in purple—along with the senior-most veterans, those with accessibility needs, and Ella and Tyson. Ella fidgeted, doing her best to avoid brushing shoulders with the senator on her left. Tyson grinned at the Lar on his right, wriggling his fingers inside the ghost’s vaporous rib cage.

Behind them, the semicircle of tiered seats was packed to overflowing with legionnaires, Lares, retired veterans, and other citizens of New Rome. I hadn’t seen a lecture hall this crowded since Charles Dickens’s 1867 Second American Tour. (Great show. I still have the autographed T-shirt framed in my bedroom in the Palace of the Sun.)

I thought I should sit in front, being an honorary wearer of bed linens, but there was simply no room. Then I spotted Lavinia (thank you, pink hair) waving at us from the back row. She patted the bench next to her, indicating that she’d saved us seats. A thoughtful gesture. Or maybe she wanted something.