His horse's breath clouded the dawn air, white on a white field. The white sky showed a narrow band of rose above the hills, the landscape's only colour. The ground glared white with frost, crunching under hooves and boots. And white rimed every branch, ice on black, though nothing could be as black as Arthur's heart.

"You would leave," he'd said, the day before. He stood. Beside him, at the Round Table, Merlin was already on his feet.

"Yes," said Merlin, in council, in sight of everyone, every knight, every lady. In the grey light from a winter window, his hair was as black as a vole's coat, his eyes the colour of the slate on a rainy mountainside.

Arthur had fallen back on anger, on the power to command. "You can't. You're my servant."

"I serve Camelot," said Merlin, his eyes mild. "And Camelot needs me to go."

"How d'you work that out?" demanded the King, slamming his hand on the great circle of the council table.

Merlin ducked his head and said nothing.

The knights shuffled and exchanged glances. It was not uncommon for the King to argue with his trusted advisor, his friend and confidante, the sorcerer Merlin. But those debates happened in private, when the two were out hunting, or in the King's chambers at morning or night. Here in council - what was this?

"I forbid it," said Arthur.

Merlin lifted his head and met the King's gaze, and the two stared at one another until Merlin, his mouth squeezed shut, turned away, and strode from the chamber.

Merlin leaned his cheek on his horse's neck, breathing in the warmth rising from the beast's black coat. "Will you carry me?" he asked, for he had been raised to respect all living things. Even the tree must give of its wood, or it will resist the axe. Even the hog, and the hare, deserve asking to the pot.

The black horse twisted its head round to butt Merlin affectionately. Merlin laughed, and patted it, and sprang into the saddle. "Come on then. And be swift, or Arthur will come after us."