" We stopped. Aly looked back the way we’d come. “Cass? Where are we headed?” Cass glanced around. “Actually . . . I’m not sure. I lost the map in the river.” “Don’t play games,” Aly snapped. “You don’t need it. You know the route.” “I did,” Cass said. “But . . . it’s not there, Aly. In my brain. I can’t call it up.” “What do you mean, not there?” Aly said. “If you’re being insecure again, like you were in Babylon, now’s the time to stop.” Cass’s eyes were hollow and scared. “I don’t feel insecure. This is so strange . . .” I looked at him closely. “Cass, can you say ‘River Nostalgikos’ backward?” “Nostalgikos . . . River?” Cass said. “Oh, dear,” Professor Bhegad muttered. “Cass, you had the ability to say anything backward, letter for letter,” Aly said. “You called it Backwardish.” Cass swallowed hard. “Dishwardback?” “The river . . .” Professor Bhegad said. “It took the ability from him.” “Skilaki warned us,” Aly said softly. “She said the river required a sacrifice . . . "

― Peter Lerangis , The Tomb of Shadows (Seven Wonders, #3)