The vow is older than the city, and the city is old enough that the stone remembers feet. I am Seren. I have seen thirty summers, which in Vael is a full adult life and not a beginning. I keep the western stair. Cael keeps the eastern, and between us the terrace where the twin moons rise, one silver, one the colour of a bruise on fruit. When two keepers bind a watch, they bind it in blood or in body. Blood is for wars. We were not at war. We were in want, and the want had finally been said aloud at dusk, where vows are legal.

"I will hold the stair if you fall," he said, the formal line. His voice went lower for the rest. "And I will have you tonight, if you take me. Not as a symbol. As a man who has watched you walk away from him for a year and is done watching."