Guillaume stood beside her, patient and serious. The sun slid over his great brutal strength. The scar was counterfeit, he said, but it seemed part of him. She would miss it. She had not seen him as marred for a long time. The line on his cheek was part of him, as if a lightning bolt slashed a tree, marking it but not making it less. She would someday see him without it, and he would be altogether different. Yet another Guillaume for her to know.

She knelt to take the small tearing off of dark bread from the hands of the priest. Guillaume did the same. Then, coming forward, the marquise and the nun.

The wine was sour stuff. The cheap glass was accidentally elegant in its simplicity. It was their wedding, so the priest gave wine as well as bread. When she had drunk, and Guillaume also, the priest wiped the lip of the glass with a white cloth and finished what was left of the wine to the dregs, making a face when he did so, but conscientious. His cuffs were deeply frayed. He had been in prison long enough to become shabby.

Father Jérôme set the cup down and lay folded cloth across it. “Another forbidden Mass in Paris. I like spitting in Robespierre’s eye. We may be interrupted at any moment, so I will spare you my homily on the sacred nature of marriage. It is somewhat boring.”

He opened his breviary so Guillaume could lay a gold ring upon the open pages.

“To the marriage, then. Guillaume, vis accípere Marguerite hic præséntem in tuam—”

Guillaume interrupted. “William. I am William Doyle Vaudreuil Markham.”

That is his true name, so our marriage will be valid. If anyone reports this, he condemns himself utterly. He does not hesitate.

Father Jérôme nodded. Truly, nothing surprised him. “William, vis accípere Marguerite . . .”

Guillaume said, “Volo.” I do.

“Marguerite, do you take William . . .”

It was her turn to decide and agree and become. Behind her, Adrian and the nun and Madame la Marquise de Barillon stood quietly.

I should make Guillaume worry, just the smallest amount. He deserves it.

But she did not. “Volo.”

“. . . faithful to her in all things as a man should be faithful to his wife, according to the command of God?”

Guillaume made his response, serious and grave, not taking his eyes off the priest.

He is not what I expected. Not what I have dreamed of. In a dozen ways, he is more powerful than any man I have known.

At Versailles, she had lived among the great men of France, the brilliant, influential men who ruled half the world. Men of privilege and ancient title, of wit and dashing charm. Guillaume was the warrior who enters the king’s hall in black armor and throws down his gauntlet. Beside Guillaume, the men of the court looked like vicious children, playing corrupt games.

He had become distant and strange to her, even while he took the ring from the priest’s hand and slid it on her finger. Guillaume married her with her mother’s ring, the wedding band of her grandmother, which he had extorted from her. Guillaume, who was William Doyle and other names she could not recall. Who was a spy. Who was English. Who must be dissuaded from menacing Papa. Who must be rescued from this prison and from death.

She was married. Somewhere between one word and the next, it had happened. She changed her name. Her nation. She was becoming English in this very moment. It swept across her, inch by inch. It was like being transformed to a tree or a statue of gold or a red deer by some careless spell.

When she glanced up, Guillaume was laughing at her silently, with every obscure and sneaky particle of himself. Perhaps he knew what she was thinking. She was wedding a mountain of slyness.

I do not know how to not love him. He was breath to her lungs, the fire of her nerves, the light of her eyes.

Father Jérôme said, “Dóminus vobíscum.”

I will not let Guillaume die. I will get him out of this dreadful place. All that I have been, all that I have done for these five years in La Flèche leads me to this moment. I will pluck him away from this prison.

“Whatever the fashion in civil law this week,” the priest said, “in God’s eyes, you are married.”

“Good.” Pounding impatience, barely held in check, radiated from Guillaume. In most marriages, it would be the eagerness of a husband to bear his wife away to the wedding bed. Here, it was Guillaume’s determination to be rid of her. “We need this written down.”

The priest opened the breviary. “In the back. Here. My brothers at Saint-Sulpice will add your names to the parish registry. I will write marriage lines for your lady as well. I need paper.”

Guillaume gestured to Adrian. “Inside. Sharpish. Find paper. I want you two out of here.”

“I’ll do better than that.” Adrian was already jerking his shirt free as he walked, headed behind a stone column. “Let me not show this to the whole bloody world. I have . . .”

Under the boy’s shirt, a wide band of linen wrapped his chest and belly. A money belt, of sorts. He pulled loose an end and unwound. “I have paper.”

“Helped yourself to some money, I see.” Guillaume didn’t sound disapproving.

“Irresistible temptation. You knew the minute I lifted it.” Adrian glanced around. Nobody was watching. He passed across a thick stack of assignats. “I’d give you the lot, but we’re going to need them. This is your paper. I collected it a night back. Decided I didn’t want to hand it over to that woman you work for.”

“I don’t work for her,” Guillaume said.

“Of course you don’t. And if that woman doesn’t terrify you, you lack imagination.” He unfolded a dozen creased sheets of pale cream writing paper. “Here. Wedding present.”

Guillaume peeled off the top sheet. It was clean on one side. He smoothed it flat against the nearest column and passed it to the priest. “Use this. Marriage lines for Marguerite.”

“I will write that with some dispatch.” The priest sat on the low wall. “This is no place for your wife.”

Guillaume took up her left hand and looked at the ring upon it. “If I live, and you want it, I’ll give you another ring.”

“I am content.”

“Then I’ll give you rubies to go with it.” He kissed her knuckles, where her ring was. “It’ll have to do. Hawker—Adrian—will take you to friends of mine. They’ll keep you safe.”

“I have my own friends in this city. I have not been transformed into a ninny by marrying you.”

The grin was so fast it didn’t twitch his features, just glinted in his eyes, like sun on water. Then it was gone. “A month from now, I want you in London.”

“I do not—”

“Maggie, listen. Go to England. To a man named Galba, in London. Hawker knows him.” Another gleam of a smile. “At Meeks Street, number seven. If there’s a child . . .” His hands tightened. She felt the trembling of his tendons, deep in his flesh where it didn’t show. “If there’s a child, Galba will make it right. He’ll make him legitimate.”

“When I go to London, you will be with me and deal with any small legalities.” She pounded her certainty into the rocks of reality as if it were an iron stake.

“If it’s a girl, name her Camilla. That was my mother’s name.”

Do not say this as if you will not be there. “Camilla. William, if it is a boy.”

The priest sat on the stone bench and wrote. The ink bottle rattled ever so slightly when he took more ink.

The round, bustling nun picked up the papers Adrian had left on the wall. “These are very dirty.” She shuffled through them, frowning. “There is writing on them. Let me run inside and find you clean sheets.”

“This will do.” The priest left off writing. “Madame, if you will sign in this book and upon this paper I have prepared.” He held the last page of the breviary open for her. The Parish of Saint-Sulpice and the date, in the old style, was written.

When one married a man like Guillaume, one must not expect an ordinary marriage register in the corner of the parish church and a procession of giggling girls and dancing and little cakes. She wrote her new name in an old breviary with a sputtering quill, then signed marriage lines that had been written on the back of some discarded letter.

“Guillaume, my son. Your signature.”

He took her place and signed the book quickly, with his English name.

The marquise signed as witness. “I do not say your father will disapprove. De Fleurignac was always an oddity.” She considered Guillaume. “I’m not certain I disapprove either.”

“Sister Anne. If you would.” The priest was patient with the nun’s observation that the breviary was not a marriage register and that banns had not been called. That the paper was dirty and creased. He looked up. “And you.”

“Me?” Adrian’s voice cracked.

“You.” The priest filled the pen with new ink and wiped the clinging drop off on the lip of the bottle. “Here.”

Adrian held the pen as if it might turn and bite him. He drew his name, letter by letter, slowly.

The priest makes him a witness because he may live. Everyone else who signs, perhaps, will not.

“It is done.” The priest gave her the marriage lines. She held the paper by the edges. The signatures had not dried. On the back there was writing. Lines and lines of it.

Guillaume was giving orders to Adrian. He could as easily have saved his breath. “If she’s in Paris when they chop me, you make sure she don’t see it. Lock her up somewhere. You’ll figure out a way to do it.”

“You want to order me to stuff the moon in a box, you go right ahead,” Adrian said. “Don’t expect anything to come of it.”