The Outsiders came on and crashed against the Winter lines. Battle ensued. From this far away, it just looked like a big, confusing mess, with everyone jostling for a better position, but I could see a few things. I saw an ogre go down when an Outsider spit acid that started eating through his eyes into his skull. I saw the Winter lines falter, and the Outsiders began pouring reinforcements into the weakness.

Then a small crew of goblins exploded out of a pile of shale at precisely the right moment, when the Outsiders were pressed almost into the Winter lines, but before reinforcements arrived. The surprise attack drove the Outsiders forward, when I could see that the "weak" regiment had been playing the Outsiders for suckers, falling back, but doing so in good order. The Outsiders had overreached themselves, and were now surrounded on all four sides by the savage troops of Winter.

The would-be invaders didn't make it.

And that was only a tiny fraction of the battle. My senses and mind alike simply could not process everything I was seeing. But my heart was beating very swiftly, and frozen fear had touched my spine like Mab's fingers.

The Outsiders wanted in.

"When?" I asked. "When did this start?"

"Oh, Harry," Mother Summer said gently.

"What?" I asked. But I had noticed something. Those layers and mounds of shale? They weren't shale.

They were bones.

Millions and millions and millions of f**ktons of bones.

"What the hell is going on here?" I breathed. "Where are we?"

"The edge of Faerie," she said. "Our outer borders. It would have taken you a decade to learn to travel out this far."

"Oh," I said. "And . . . and it's like this?"

"In essence," Mother Summer said. She stared sadly out over the plain. "Did you think Mab spent all her days sitting in her chair and dealing with her backstabbing courtiers? No, Sir Knight. Power has purpose."

"What happens if they get in?" I asked.

Mother Summer's lips thinned. "Everything stops. Everything."

"Holy crap," I muttered. "Does Summer have a place like this, too, then?"

Mother Summer shook her head. "That was never its task. Your Council's estimate was fairly close, counting only those troops protecting the hearts of Winter and Summer. Mab has more than that. She needs them-for this."

I felt like I'd been hit repeatedly in the head with a rubber hammer. "So . . . Mab's troops outnumber yours by a jillion."

"Indeed."

"So she could run you over at any time."

"She could," Mother Summer said, "if she were willing to forfeit reality."

I scanned the length of the wall nervously. It looked like it went on forever-and there was fighting all along its length.

"You're telling me thatthis is why Mab has her power? To . . . to protect the borders?"

"To protect all of you from the Outsiders, mortal."

"Then why does Titania have hers?" I asked.

"To protect all of you from Mab."

I swallowed.

"Titania cannot match Mab's forces, but she can drag Mab personally into oblivion with her-and Mab knows it. Titania is the check to her power, the balance."

"If Mab dies . . ." I began.

She swept a hand along the length of the wall. "A spoiled, sadistic, murderous, and inexperienced child will have control of all of that."

Hell's bells. I rubbed at my eyes, and as I did, I connected some dots and realized something else.

"This is a siege," I said. "Those guys out there are attacking the walls. But there are others trying to dig their way in so that they can open the gates for their buddies. That's what the adversary is. Right? A sapper, an infiltrator."

Mother Summer said, "There, you see? You possess the potential to be quite intelligent. Do stay beside me, dear." And she started walking firmly toward the massive gates.

It didn't take us long to get there, but as we came up to the base of the wall and walked along it, we started drawing the eyes of the wall's defenders. I felt myself growing tenser as a marching column of armored Sidhe soldiers came stepping lightly along the ground behind us, catching up quickly.

Mother Summer guided me slightly aside so that we weren't in the column's way, and they started going by us. I didn't think much of it until someone at the front of the column called out in a clear voice, and as one the Sidhe came to a halt with a solid, simultaneous stomp of a couple of hundred boots. The voice barked another command, and the Sidhe all turned to face us.

"Uh-oh," I said.

Mother Summer touched my hand with hers, and reassurance bathed me like June sunshine. "Shhh."

The voice barked another command, and as one the Sidhe lowered themselves to one knee and bowed their heads.

"Good morrow, cousins," Mother Summer said, her voice solemn. She took her hand off my arm and passed it in a broad, sweeping arch over the kneeling soldiers. Subtle, subtle power thrummed delicately in the air. "Go forth with my blessing."

One of the soldiers in the lead of the column rose and bowed to her, somehow conveying gratitude. Then he snapped out another loud command, and the column rose, turned, and continued its quickstep march.

"Huh," I said.

"Yes?" asked Mother Summer.

"I was sort of expecting . . . something else."

"Winter and Summer are two opposing forces of our world," she said. "But we are of our world. Here, that is all that matters. And showing respect to one's elders is never unwise."