Royster gave him a dry look. "Shows what you knew, doesn't it?" he said irreverently. "Oh, there are little rhymes a mage might use to remember the sequence of what must be done, but the words themselves don't do a thing. You could write every magic 'spell' as high as a man on the barn wall, but if you don't have the power to start with, all you'd have is a strange rhyme. And a bad one at that."
"You and the Sisterhood have told me what a Summoner may and may not do. You've listed for me every kind of ghost and spirit and made me memorize all the things that can bind a spirit to this world. And between me and them stands only death," Tris said quietly. "But what is death?"
Royster pulled a coin from his pocket. "What's on the front?" He held the gold up in the firelight so that it glistened.
"The image of the king."
"And on the back?"
"The crown of Principality."
"Can you cut the coin to separate the front from the back?" Royster handed him the coin.
Tris took it and turned it in his fingers, then finally shook his head. "How could I tell where one stopped and the other started?"
Royster nodded. "Exactly. So it is with death. On one side of death, a person is alive. And on the other, only the spirit remains. But death itself? It's only the somewhere between awake and asleep. For those without your gift, it's a line that can be crossed only once, and in one direction. But for a Summoner, it's a doorway that can be entered and exited at will."
Tris turned the coin thoughtfully in his fingers. "The dead aren't really at rest, are they?"
"That's the true purpose of a Summoner," Royster said. "To give rest to spirits that would otherwise wander, or who cannot find their rest. And to defend them against those who would hold them against their will, or snuff out their energy for power's sake, or bind them for evil.
"A land mage knows the secrets of the world around him, the stories of the birds and animals, the voices of every living thing. An air mage speaks
to the winds and the weather. The sea itself answers a water mage, and all the things that live in it obey his commands. And a fire mage knows the mysteries of the depths of the world," Royster said. "But only to a spirit mage is it given to summon the dead and ease their pain and to know the mysteries of life itself. That's why the Lady permits so few to share the power, and why so often the power corrupts."
"How can I know if I'm being corrupted, too?"
