We nodded, quickly.

"That is unfortunate. Forget what you learned. I do not like to be squeezed by legs or tugged at. The one in front will hold on to my waist, the one behind will hold on to him. If you feel that you are going to fall, speak up."

Achilles and I exchanged a look, quickly.

He stepped forward.

"How should I- ?"

"I will kneel." His horse legs folded themselves into the dust. His back was broad and lightly sheened with sweat. "Take my arm for balance," the centaur instructed. Achilles did, swinging his leg over and settling himself.

It was my turn. At least I would not be in front, so close to that place where skin gave way to chestnut coat. Chiron offered me his arm, and I took it. It was muscled and large, thickly covered with black hair that was nothing like the color of his horse half. I seated myself, my legs stretched across that wide back, almost to discomfort.

Chiron said, "I will stand now." The motion was smooth, but still I grabbed for Achilles. Chiron was half as high again as a normal horse, and my feet dangled so far above the ground it made me dizzy. Achilles' hands rested loosely on Chiron's trunk. "You will fall, if you hold so lightly," the centaur said.

My fingers grew damp with sweat from clutching Achilles' chest. I dared not relax them, even for a moment. The centaur's gait was less symmetrical than a horse's, and the ground was uneven. I slipped alarmingly upon the sweat-slick horsehair.

There was no path I could see, but we were rising swiftly upwards through the trees, carried along by Chiron's sure, unslowing steps. I winced every time a jounce caused my heels to kick into the centaur's sides.

As we went, Chiron pointed things out to us, in that same steady voice.

There is Mount Othrys.

The cypress trees are thicker here, on the north side, you can see.

This stream feeds the Apidanos River that runs through Phthia's lands.

Achilles twisted back to look at me, grinning.

We climbed higher still, and the centaur swished his great black tail, swatting flies for all of us.

CHIRON STOPPED SUDDENLY, and I jerked forward into Achilles' back. We were in a small break in the woods, a grove of sorts, half encircled by a rocky outcrop. We were not quite at the peak, but we were close, and the sky was blue and glowing above us.

"We are here." Chiron knelt, and we stepped off his back, a bit unsteadily.

In front of us was a cave. But to call it that is to demean it, for it was not made of dark stone, but pale rose quartz.

"Come," the centaur said. We followed him through the entrance, high enough so that he did not need to stoop. We blinked, for it was shadowy inside, though lighter than it should have been, because of the crystal walls. At one end was a small spring that seemed to drain away inside the rock.

On the walls hung things I did not recognize: strange bronze implements. Above us on the cave's ceiling, lines and specks of dye shaped the constellations and the movements of the heavens. On carved shelves were dozens of small ceramic jars covered with slanted markings. Instruments hung in one corner, lyres and flutes, and next to them tools and cooking pots.

There was a single human-sized bed, thick and padded with animal skins, made up for Achilles. I did not see where the centaur slept. Perhaps he did not.

"Sit now," he said. It was pleasantly cool inside, perfect after the sun, and I sank gratefully onto one of the cushions Chiron indicated. He went to the spring and filled cups, which he brought to us. The water was sweet and fresh. I drank as Chiron stood over me. "You will be sore and tired tomorrow," he told me. "But it will be better if you eat."

He ladled out stew, thick with chunks of vegetables and meat, from a pot simmering over a small fire at the back of the cave. There were fruits, too, round red berries that he kept in a hollowed outcropping of rock. I ate quickly, surprised at how hungry I was. My eyes kept returning to Achilles, and I tingled with the giddy buoyancy of relief. I have escaped.

With my new boldness, I pointed to some of the bronze tools on the wall. "What are those?"

Chiron sat across from us, his horse-legs folded beneath him. "They are for surgery," he told me.

"Surgery?" It was not a word I knew.

"Healing. I forget the barbarities of the low countries." His voice was neutral and calm, factual. "Sometimes a limb must go. Those are for cutting, those for suturing. Often by removing some, we may save the rest." He watched me staring at them, taking in the sharp, saw-toothed edges. "Do you wish to learn medicine?"

I flushed. "I don't know anything about it."

"You answer a different question than the one I asked."

"I'm sorry, Master Chiron." I did not want to anger him. He will send me back.

"There is no need to be sorry. Simply answer."

I stammered a little. "Yes. I would like to learn. It seems useful, does it not?"

"It is very useful," Chiron agreed. He turned to Achilles, who had been following the conversation.

"And you, Pelides? Do you also think medicine is useful?"

"Of course," Achilles said. "Please do not call me Pelides. Here I am-I am just Achilles."

Something passed through Chiron's dark eyes. A flicker that was almost amusement.

"Very well. Do you see anything you wish to know of?"

"Those." Achilles was pointing to the musical instruments, the lyres and flutes and seven-stringed kithara. "Do you play?"

Chiron's gaze was steady. "I do."

"So do I," said Achilles. "I have heard that you taught Heracles and Jason, thick-fingered though they were. Is it true?"

"It is."

I felt a momentary unreality: he knew Heracles and Jason. Had known them as children.

"I would like you to teach me."

Chiron's stern face softened. "That is why you have been sent here. So that I may teach you what I know."

IN THE LATE AFTERNOON LIGHT, Chiron guided us through the ridges near the cave. He showed us where the mountain lions had their dens, and where the river was, slow and sun-warm, for us to swim.

"You may bathe, if you like." He was looking at me. I had forgotten how grimy I was, sweat-stained and dusty from the road. I ran a hand through my hair and felt the grit.

"I will too," Achilles said. He pulled off his tunic and, a moment after, I followed. The water was cool in the depths, but not unpleasantly so. From the bank Chiron taught still: "Those are loaches, do you see? And perch. That is a vimba, you will not find it farther south. You may know it by the upturned mouth and silver belly."

His words mingled with the sound of the river over its rocks, soothing any strangeness there might have been between Achilles and me. There was something in Chiron's face, firm and calm and imbued with authority, that made us children again, with no world beyond this moment's play and this night's dinner. With him near us, it was hard to remember what might have happened on the day by the beach. Even our bodies felt smaller beside the centaur's bulk. How had we thought we were grown?

We emerged from the water sweet and clean, shaking our hair in the last of the sun. I knelt by the bank and used stones to scrub the dirt and sweat from my tunic. I would have to be naked until it dried, but so far did Chiron's influence stretch that I thought nothing of it.

We followed Chiron back to the cave, our wrung-dry tunics draped over our shoulders. He stopped occasionally, to point out the trails of hare and corncrakes and deer. He told us we would hunt for them, in days to come, and learn to track. We listened, questioning him eagerly. At Peleus' palace there had been only the dour lyre-master for a teacher, or Peleus himself, half-drowsing as he spoke. We knew nothing of forestry or the other skills Chiron had spoken of. My mind went back to the implements on the cave's wall, the herbs and tools of healing. Surgery was the word he had used.

It was almost full dark when we reached the cave again. Chiron gave us easy tasks, gathering wood and kindling the fire in the clearing at the cave's mouth. After it caught, we lingered by the flames, grateful for their steady warmth in the cooling air. Our bodies were pleasantly tired, heavy from our exertions, and our legs and feet tangled comfortably as we sat. We talked about where we'd go tomorrow, but lazily, our words fat and slow with contentment. Dinner was more stew, and a thin type of bread that Chiron cooked on bronze sheets over the fire. For dessert, berries with mountain-gathered honey.

As the fire dwindled, my eyes closed in half-dreaming. I was warm, and the ground beneath me was soft with moss and fallen leaves. I could not believe that only this morning I had woken in Peleus' palace. This small clearing, the gleaming walls of the cave within, were more vivid than the pale white palace had ever been.

Chiron's voice, when it came, startled me. "I will tell you that your mother has sent a message, Achilles."

I felt the muscles of Achilles' arm tense against me. I felt my own throat tighten.

"Oh? What did she say?" His words were careful, neutral.

"She said that should the exiled son of Menoitius follow you, I was to bar him from your presence."

I sat up, all drowsiness gone.

Achilles' voice swung carelessly in the dark. "Did she say why?"

"She did not."

I closed my eyes. At least I would not be humiliated before Chiron, the tale of the day at the beach told. But it was bare comfort.

Chiron continued, "I assume you knew of her feelings on the matter. I do not like to be deceived."

My face flushed, and I was glad of the darkness. The centaur's voice sounded harder than it had before.

I cleared my throat, rusty and suddenly dry. "I'm sorry," I heard myself say. "It is not Achilles' fault. I came on my own. He did not know that I would. I did not think-" I stopped myself. "I hoped she would not notice."

"That was foolish of you." Chiron's face was deep in shadow.

"Chiron-" Achilles began, bravely.

The centaur held up a hand. "As it happens, the message came this morning, before either of you arrived. So despite your foolishness, I was not deceived."

"You knew?" This was Achilles. I would never have spoken so boldly. "Then you have decided? You will disregard her message?"

Chiron's voice held a warning of displeasure. "She is a goddess, Achilles, and your mother besides. Do you think so little of her wishes?"

"I honor her, Chiron. But she is wrong in this." His hands were balled so tightly I could see the tendons, even in the low light.

"And why is she wrong, Pelides?"

I watched him through the darkness, my stomach clenching. I did not know what he might say.

"She feels that-" He faltered a moment, and I almost did not breathe. "That he is a mortal and not a fit companion."

"Do you think he is?" Chiron asked. His voice gave no hint of the answer.

"Yes."

My cheeks warmed. Achilles, his jaw jutting, had thrown the word back with no hesitation.

"I see." The centaur turned to me. "And you, Patroclus? You are worthy?"

I swallowed. "I do not know if I am worthy. But I wish to stay." I paused, swallowed again. "Please."

There was silence. Then Chiron said, "When I brought you both here, I had not decided yet what I would do. Thetis sees many faults, some that are and some that are not."

His voice was unreadable again. Hope and despair flared and died in me by turns.

"She is also young and has the prejudices of her kind. I am older and flatter myself that I can read a man more clearly. I have no objection to Patroclus as your companion."

My body felt hollow in its relief, as if a storm had gone through.

"She will not be pleased, but I have weathered the anger of gods before." He paused. "And now it is late, and time for you to sleep."

"Thank you, Master Chiron." Achilles' voice, earnest and vigorous. We stood, but I hesitated.

"I just want-" My fingers twitched towards Chiron. Achilles understood and disappeared into the cave.

I turned to face the centaur. "I will leave, if there will be trouble."

There was a long silence, and I almost thought he had not heard me. At last, he said: "Do not let what you gained this day be so easily lost."

Then he bade me good night, and I turned to join Achilles in the cave.

Chapter Nine.

THE NEXT MORNING I WOKE TO THE SOFT SOUNDS OF Chiron getting breakfast ready. The pallet was thick beneath me; I had slept well, and deeply. I stretched, startling a little when my limbs bumped against Achilles, still asleep beside me. I watched him a moment, rosy cheeks and steady breaths. Something tugged at me, just beneath my skin, but then Chiron lifted a hand in greeting from across the cave, and I lifted one shyly in return, and it was forgotten.

That day, after we ate, we joined Chiron for his chores. It was easy, pleasurable work: collecting berries, catching fish for dinner, setting quail snares. The beginning of our studies, if it is possible to call them that. For Chiron liked to teach, not in set lessons, but in opportunities. When the goats that wandered the ridges took ill, we learned how to mix purgatives for their bad stomachs, and when they were well again, how to make a poultice that repelled their ticks. When I fell down a ravine, fracturing my arm and tearing open my knee, we learned how to set splints, clean wounds, and what herbs to give against infection.

On a hunting trip, after we had accidentally flushed a corncrake from its nest, he taught us how to move silently and how to read the scuffles of tracks. And when we had found the animal, the best way to aim a bow or sling so that death was quick.

If we were thirsty and had no waterskin, he would teach us about the plants whose roots carried beads of moisture. When a mountain-ash fell, we learned carpentry, splitting off the bark, sanding and shaping the wood that was left. I made an axe handle, and Achilles the shaft of a spear; Chiron said that soon we would learn to forge the blades for such things.

Every evening and every morning we helped with meals, churning the thick goat's milk for yogurt and cheese, gutting fish. It was work we had never been allowed to do before, as princes, and we fell upon it eagerly. Following Chiron's instructions, we watched in amazement as butter formed before our eyes, at the way pheasant eggs sizzled and solidified on fire-warmed rocks.

After a month, over breakfast, Chiron asked us what else we wished to learn. "Those." I pointed to the instruments on the wall. For surgery, he had said. He took them down for us, one by one.

"Careful. The blade is very sharp. It is for when there is rot in the flesh that must be cut. Press the skin around the wound, and you will hear a crackle."

Then he had us trace the bones in our own bodies, running a hand over the ridging vertebrae of each other's backs. He pointed with his fingers, teaching the places beneath the skin where the organs lodged.