In Knightsbridge, in days gone by, there lived a glass-­painter called William the glazier. Will had learned to make glass at the knee of his father, learned which metallic salts--cobalt and copper, gold and iron and -manganese--to add to the molten sand and beechwood ash to create the most glorious colors.
 
But Will was born also of an alchemist, and at his mother’s side he learned the secrets of combining common things of nature to create a new thing, something not of nature, not quite, something close to magical. In those days, unless it hinted of heresy, magic was tolerated at its most innocuous levels: the soothsayer did brisk business at the fair, for example. Will’s mother reasoned that if she could learn the secret of turning something worthless into gold, the same method might be used to make more worthy the human soul. Alas, she expired--the result of an unfortunate experiment--before she could prove her theory, and Will let alchemy alone. Mostly.
 
But one day Will thought to combine his two interests--alchemy and glass--to make a gift for his wife. Something special, something rare. And it worked. Like magic.
 
 
 
 “A mirror,” Catherine breathed.
 
It was near sunset, and the cathedral was empty, except for the glass-­painter and his wife and a pair of jenny wrens who’d got in through the half-­completed wall of stained glass. Will had been hired by the old king, Ranulph, to create the great rose window--years in the making--that would finish the cathedral’s west end.
 
“Not just any mirror,” said Will, coming round the long worktable with the object--a circle of pale glass, bound and backed with lead, and with a handle of carved bone. “I’ve made a pair, as we two are a pair.” Will glanced around, as if among the solder and snips and shadows there might be another ear to listen, then gave the mirror to Catherine. “Look! Look into it!”
 
Catherine ran a hand absently over her belly--the baby would be born before the month was out, by the midwife’s measure--and lifted the mirror. First her face clouded with confusion. Then her eyes lit up and her lips twitched.
 
“What do you see?” Will held his breath.
 
“I see you!” Catherine smiled and cupped Will’s cheek, then looked again into the mirror. “Your eyes, green as spring,” she said, gazing into the glass. “What is it about? How . . . ?”
 
Will grinned wildly and raked his hands through his hair so that tufts stood alert in all directions. “Several attempts, many secret hours at the kiln. Cherrywood ash instead of beech. And to the ash I added this and that: chamomile for love, coltsfoot for visions, dandelion root for divination, fern leaf for clarity, and”--he rubbed his hands together--“primrose. I’m quite proud of the primrose. That’s where the truth comes from. Yes, that’s what I meant to say! The mirror reflects the beholder--inside and out!” He grabbed the glass from Catherine and ran his fingers over the words etched on the back. “I call the magic mirror Lux Vera.”
 
Catherine shook her head, uncomprehending.
 
“ ‘True Light.’ You see?” Again Will touched the words. “Because it shows the heart’s true light, just as my great rose window shows the true light of God. When I look into the mirror, I see you, my love. And this proves I’ve done the magic right, for you see me!”
 
Catherine’s delighted laughter was cut short by the scrape of the west porch door on the stone flooring.
 
“William Glazier!” came a shout. Lord Geoffrey, king consort, had been checking Will’s progress on the rose window with irritating frequency.
 
Will shoved the mirror on the shelf beneath the worktable. He didn’t trust Lord Geoffrey. Just last week he’d seen him toss a mouser from a parapet.
 
The king consort advanced along the aisle, the hem of his mantle swirling with the force of his stride. When he reached them, the cloak swelled and settled like a vulture’s wings.
 
“My lord!”
 
His Lordship acknowledged Will’s greeting with a curt nod and turned his attention to the worktable, on which a panel of stained glass was taking shape. There, three figures met between lines of lead.
 
One was Queen Isobel, daughter and heir of Ranulph, hair flowing in saffron swirls and waves, while down her cheek trailed a widow’s tears.
 
The second, fair Armand, her late husband, dead in the wars not one year past.
 
The third, Armand’s closest comrade: Lord Geoffrey himself, husband now to Isobel and, as such, the new king consort. Will had painted his likeness--thin nose, hollow cheek, and pointed tuft of beard--with confident brushstrokes, as he had all the masterful detail in the great rose window under construction. Then he had fused paint to glass in the kiln at Knightsbridge Wood.
 
Geoffrey stroked his beard, then tugged at the tips of his leather gloves, removing them finger by finger. “We fought for God and kingdom, Armand and I,” he said, and tucked the gloves in his belt. “Thank the saints I could be of comfort to his widow.”
 
Catherine smiled fondly. “And how is Queen Isobel? Expecting any moment, the midwife tells us?” Catherine, a distant cousin of Armand, could afford this slight familiarity with the royal family.
 
“Our little heir,” Geoffrey crowed. “A son this night, I pray.”
 
“But . . .” Will glanced at the queen and Armand in the glass. “What of . . .”
 
“Poor Armand, never laid eyes upon his infant daughter.” Geoffrey sniffed. “I’m honor-­bound to raise the girl as my own, of course. For I loved Armand like a brother.”
 
“Of course.” Will swallowed. There had been rumors. . . . The midwife had said Geoffrey was clearly displeased that Armand’s child, and not his, would one day rule. As Will said a quick prayer for the continued health of Queen Isobel, Geoffrey all at once bent and swept up the mirror from the shelf.
 
“No! It’s--it’s a gift for Catherine,” Will stammered. He put his hand over the mirror.
 
But Lord Geoffrey pushed the glass-­painter aside. Lips parted, he drew the mirror closer in the fading light, and suddenly his grip on the bone handle whitened his knuckles. He pressed the mirror to his chest, then looked again with open hunger at the glass. “God’s wounds,” he sputtered at last, “what magic is this?”
 
“Magic?” Will twisted the hem of his tunic in his hands.
 
Now Lord Geoffrey spoke slowly, distinctly. “The power to make such a mirror might be judged born of the Devil,” he said. “There are tests, Will Glazier.”
 
Catherine gasped, and Geoffrey glanced sharply in her direction.
 
“The hot iron, the sinking in the River Severn . . . ,” Geoffrey went on. “A trial by ordeal can never end well. But,” he said, stroking his pointed beard, “I wonder if we might work . . . together.” Geoffrey smiled coldly at Will. “I’m a generous man. I will keep secret your talent. You have my word.” And he thrust out his hand.
 
Will hesitated only a moment before taking Lord Geoffrey’s right hand in his. At the same time, he reached to the mirror with his left, glanced at the glass, then stared, transfixed. “That’s . . .” Will’s eyes cut to Geoffrey’s face, and back to the glass.
 
For long moments the two men were locked in strange, silent battle; then the mirror dropped to the flagstone with a delicate, final, crack.
 
“Idiot!” Geoffrey’s cheeks reddened with angry spots.
 
“An accident, my lord. Apologies. So clumsy.” Will knelt to pick up the shards of glass with hands that shook.
 
“You saw something,” Geoffrey hissed, breathing with effort. “What was it?”
 
Rising, Will forced himself to look steadily into Lord Geoffrey’s eyes. “I--only you, of course. I can make another mirror. One fit for a . . . king.”
 
Geoffrey yanked the gloves from his belt and tugged them on, jaw clenched, his gaze never leaving Will’s face. “I will have another.” His voice dropped to a whisper, but it seemed to fill the cathedral. “Just like that one.”