" The moment his hand closed about the stone, light blazed from it again, raying out through his fingers. For the first time Tessa saw that he had a design on the back of his hand, drawn there as if in black ink. It looked like an open eye. "As for the temperature of Hell, Miss Gray," he said, "let me give you a piece of advice. The handsome young fellow who's trying to rescue you from a hideous fate it never wrong. Not even if he says the sky is purple and made of hedgehogs. "

― Cassandra Clare , Clockwork Angel (The Infernal Devices, #1)