She knelt to draw markings in the sand, then prayed in her language, making certain gestures first to the north, then to the east, then to the south, then to the west. From her pouch she drew pebbles, and she laid a green one to the north, a reddish-orange one to the east, a dull brown one to the south, and a white one to the west. Sand glistened under the full moon. Rivulets of water coursed toward the hidden sea, a hundred fingerlets probing west through the seabed.

Were they getting wider? Was the tide coming in?

“We stand halfway,” she said, rising. She unstoppered one of the leather bottles and allowed him three swallows. “We must walk quickly.”

The horse snorted nervously. A wind touched his cheek. Then it was still again. They walked on.

“Teach me how to pray to your gods,” he said suddenly.

After a long time, she said, “My gods are not your gods, and we do not pray to them as you pray. If you will not pray to the heaven god of your people, then you must find another god to pray to. You tell me before that your grandmother is a wise woman. Pray to the gods of your mother’s mothers. Then you will be happy, and maybe they will protect you.”

A narrow channel of water lay before them. She waded in, and he followed. The water was only ankle-deep, but beyond it lay a second channel, then a third, each one deeper than the last. They slogged over yet another sandbank to a fourth channel, and here she had to hike up her skirt to her hips to keep it from getting wet.

Unseen fish nibbled at his legs. When he turned to look behind, he saw only a dark line marking the shore. The horse grew more skittish. Water stirred and coiled in eddies like a nest of snakes coming awake. Wind breathed on his neck. The great monster was exhaling: the tide was coming in.

“How soon?” he asked hoarsely.

“There,” she said.

There. It loomed before them out of the seabed. Looking up, he stubbed his toes on stone. She led them up a shallow-sloped stone ramp that emerged seamlessly from the sea floor as from a forgotten city buried beneath the sand. As they walked, the water swirled in around them, swallowing the glistening sands and the narrow channels, all of it subsumed until only they on the stone ramp walked dry-footed as the sea returned and with it the night wind. The moon rode high in the sky, drowning the stars.

His grandmother had named the moon “the Pale Hunter,” she who watches over the life and death of animals, and at full moon her strength was greatest.

“I pray you, Great Hunter,” he murmured, trying out the words, feeling awkward, “give me strength. Lend me some of your power.”

An island rose steep-sided before them, a stone fort with gleaming marble walls. They climbed until the ramp ended at the base of an ebony gate. A path paved with black stone curled away on either side, a wall rising sheer on one side and cliff dropping away sheer on the other.

She led them to the left, deocil, along the path as the waters rose along the base of the hill, slowly submerging the ramp.

“What if it comes up higher?” he asked nervously. She did not answer him, only walked forward on the black path that circled the island. He tried to remember the prayers his grandmother had spoken, but the words had fled long since, leaving only the memory of her, old and gnarled but hale, with a wicked sense of humor. She had after many years agreed to pray before the altar of the Circle God, and the frater had rejoiced and given the entire village a great feast to celebrate her conversion, and his parents had wept with joy that she had walked at last into the Light. But he had seen her hide a carved wooden figure of The Fat One, the bringer of wisdom and plenty, in the skirts of the hearth; every time she knelt and prayed before the holy image of the Mother and Father of Life, she was really praying to The Fat One.

They walked forever on the black path, but when they returned to the ebony gate, the waters lapped the stone ramp two man-lengths from them. It was still rising.

“Now we are outside,” she said. She drew her knife and drew the blade over her palm. She smeared her blood over the ebony surface of the gate, then cut Zacharias’ hand in the same manner, and nicked the horse on the shoulder; this blood, too, she smeared on the gate.

Her fingers probed the shadows beside the gate, caught a lever, and pulled. The door swung open outward on silent hinges. She stepped over the threshold, and he followed her only to find that he stood in a narrow lane that ran parallel to the black stone path outside. High stone walls rose on either side. The horse balked, but when seawater lapped the threshold to drown its hooves, it bolted inside.

She tugged the gate closed against the rising tide. He glanced up anxiously: were the stone walls high enough, and watertight enough, to keep them safe from the waters? But when he knelt to brush the ground, it was as dry as bleached bone racked by a summer of rainless heat. She began to walk to the right, widdershins, and he followed her. After about the time it would take to sing the service of Terce, a short hour, they returned back to where they had started, at the ebony gate.