The fire-heart tried to roar up and out of the bottle as soon as I broke the seal: I found I had to hold the stopper in place. The potion fell back sullenly, and I whipped out the stopper and poured a drop—the least, the slightest drop—on the very end of the bundled log. The log went up in flames so quickly that Danka had scarcely a moment to throw it over the fence, hastily, and afterwards turned and thrust her hand into a snowbank, wincing: her fingers were already blistered and red. I was busy jamming the stopper back in, and by the time I looked up, half the pen was engulfed, the cattle bellowing furiously.

We were all taken aback by the ferocity of the magic, though we’d all heard tales of fire-heart—it figured in endless ballads of warfare and siege, and also in the stories of its making, how it required a thousandweight of gold to make a single flask, and had to be brewed in cauldrons made of pure stone, by a wizard of surpassing skill. I carefully hadn’t mentioned to anyone that I didn’t have permission to take the potions from the tower: if the Dragon was going to be angry with anyone, I meant for him to be angry with me alone.

But hearing stories about it wasn’t the same as seeing it in front of our faces. We were unprepared, and the sickened cattle were already in a frenzy. Ten of them clumped together and bore down on the back wall, smashing against it heedless of the waiting stakes and prods. And all of us were terrified of being gored or bitten, even of touching them; the Wood’s evil could spread so easily. The handful of defenders fell back, and Danka was shouting furiously as the fence began to give way.

The Dragon had taught me, with endless labor and grim determination, several small spells of mending and fixing and repair, none of which I could cast very well. Desperation made me try: I climbed up onto my father’s empty sled and pointed at the fence and said, “Paran kivitash farantem, paran paran kivitam!” I had missed a syllable somewhere, I knew it, but I must have been close enough: the largest bar, splintering, jumped back whole into place and suddenly put out twigs with new leaves, and the old iron cross-braces straightened themselves out.

Old Hanka, who alone had held her ground—“I’m too sour to die,” she said afterwards, by way of dismissing credit for her bravery—had been holding only the stump of a rake, the head of it already broken off and jammed between the horns of one of the oxen. Her stubby stick turned into a long sharpened rod of bright metal, steel, and she jabbed it at once straight into the open bellowing maw of the cow pushing on the fence. The spear pierced through and through and came out the back of the cow’s skull, and the huge beast fell heavily against the fence and sagged dead to the ground, blocking the others from coming at it.

That proved to be the worst of the fight. We held them everywhere else, for a few minutes longer, and the task grew easier: they were all on fire by then, a terrible stink going up that twisted the stomach. They lost their cunning in panic and became merely animals again, throwing themselves futilely against the fence walls and one another until the fire brought them down at last. I used the mending charm twice more, and by the end was sagging against Kasia, who had climbed into the wagon to hold me up. The older children were running everywhere breathless with buckets of half-melted snow to put out any sparks that fell on the ground. Every last man and woman labored to exhaustion with their prods, faces red and sweaty with heat, backs freezing in the cold air, but together we kept the beasts penned, and neither the fire nor their corruption spread.

Finally the last cow fell. Hissing smoke and fat crackled on inside the fire. We all sat exhausted in a loose ring around the pen, keeping out of the smoke, watching as the fire-heart settled down and burned low, consuming everything down to ashes. Many coughed. No one spoke or cheered. There was no cause for celebration. We were all glad to see the worst danger averted, but the cost was immense. Jerzy wasn’t the only one who would be impoverished by the fire.

“Is Jerzy still alive?” I asked Kasia softly.

She hesitated, and then nodded. “I heard he was taken badly,” she said.

The Wood-sickness wasn’t always incurable—the Dragon had saved others, I knew. Two years ago an easterly wind had caught our friend Trina on the riverbank while she was doing some washing. She came back stumbling and sick, the clothing in her basket coated with a silver-grey pollen. Her mother stopped her coming in. She threw the clothes on the fire and took Trina down to the river and dunked her over and over, while Danka sent a fast rider to Olshanka immediately.

The Dragon had come that night. I remembered I had gone over to Kasia’s house and we’d watched together from her backyard. We didn’t see him, only a cold blue light, flaring from the upstairs window of Trina’s house. In the morning, Trina’s aunt told me at the well that she was going to be all right: two days later Trina was up and about, herself again, only a little tired like someone who’d had a bad cold, and even pleased because her father was digging a well by their house, so she wouldn’t ever have to go all the way to the river to do the washing again.

But that had only been a single malicious gust of wind, a drift of pollen. This—this was one of the worst takings I remembered. So many cattle sickened, so horribly, and able to spread their own corruption onward so quickly: that was a sure sign that it was very bad.

Danka had heard us speaking about Jerzy. She came over to the wagon and looked in my face. “Is there anything you can do for him?” she asked bluntly.

I knew what she was really asking. It was a slow and dreadful death, if the corruption wasn’t purged. The Wood consuming you like rot eating away at a fallen tree, hollowing you out from the inside, leaving only a monstrous thing full of poison, which cared for nothing but to spread that poison onward. If I said there was nothing I could do, if I admitted I knew nothing, if I confessed that I was spent—with Jerzy so badly taken and the Dragon a week and more from coming—Danka would give the word. She would lead a few men to Jerzy’s house. They would take Krystyna away to the other side of the village. The men would go inside, and come out again with a heavy shroud, and bring his body back here. They would throw it on the pyre with the burning cattle.

“There are things I can try,” I said.

Danka nodded.

I clambered slowly and heavily down from the wagon. “I’ll come with you,” Kasia said, and linked her arm in mine to support me: she could tell I needed the help, without a word said. We walked slowly together towards Jerzy’s house.