The guardians didn't wait on their landings for long.
The one on the second landing moved first. It stepped off its platform and onto the stair below it, and then the one on the third landing did the same, and the one on the fourth after that, until all the way up the inside of the tower the black figures were walking down the spiral toward them, two abreast, with the slow, even steps of something that would not get tired.
Nathan watched them come and did the sum in his head. The stair was as wide as a cart, which was room for two of them side by side, or for one of his summons to fight comfortably. There was a wall on one side and a drop to the stone floor on the other, and above them were thirty landings, maybe more, and a guardian on every one.
"We can't fight them one at a time," he said. "There are too many, and they'll just keep coming until one of us is too tired to lift a sword. We have to use the drop."
