Sophie squinted across purple hills and saw Hort’s shadow trudging along the trail. “Oh he’ll be fine. His father was a pirate, for goodness’ sakes—”

“No,” said Agatha. “That.”

She was watching a mirage far, far away, barely discernible against the gray sky. The colors were thin and impressionistic, like one of August Sader’s paintings, but Agatha could make out the outlines of a village: turreted cottage houses, yellow schoolhouse, crooked clock tower, shielded by a protective bubble. . . . Her mouth fell open.

“Gavaldon. That’s . . . Gavaldon.”

“The beginnings of it, at least,” said Merlin.

Agatha gazed at him, suddenly understanding. “Every old story changed brings him closer to the Reader World. That’s what he said.”

“And he meant it literally,” said the wizard. “It seems your fellow Readers are reading his new stories.”

Agatha and Sophie both looked confused.

“You see, as long as Readers believe in the old fairy tales—and the power of Good to triumph over Evil—the School Master has no access to their world, other than to take two students to school every four years. Indeed, he confessed this weakness to Agatha himself,” said Merlin, studying the mirage carefully. “But once Readers read the new stories and begin to lose their faith in Good, their world gets closer and closer to the School Master’s grasp. With every hero’s death, that protective shield will weaken . . . the mirage will sharpen . . . until at last the gates will open to his Dark Army. For there is something in your village the young School Master needs to complete your fairy tale. Something he needs to destroy Good forever. And whatever it may be, it is something he will surely get . . . unless we destroy that ring.”

Merlin, Agatha, and Tedros all turned to Sophie.

“I don’t understand, Sophie,” Tedros said, glaring at the gold circle on her finger. “What are you waiting for?”

Sophie bristled. “Teddy, look dear! What a lovely lunch Merlin’s served us! You must be famished.” She pulled him down to the picnic spread before looking up at Agatha. “You and Merlin best be on your way, shouldn’t you, Aggie? Don’t want any villains catching us here in broad daylight.”

Agatha could see Merlin about to expound on the wonder of Gillikin fairies, but she nudged him and Merlin grinned oafishly, picking up the hint.

Later, as the two of them crossed the abandoned lake village of Urthur, hopping between what seemed like an enormous game board of waterpuddles, Agatha could still see Merlin smiling. She assumed it was because there was something primal about jumping over puddles reflecting the pink-and-blue sunset, clearing hurdles or missing by inches and splish-sploshing ice-cold water with giggly shrieks, like two children playing leapfrog.

But Merlin wasn’t smiling at any of that.

He was smiling at Agatha.

Not just because it was she who’d known to give her friends privacy on that hill instead of him or that it was the wizard now huffing and puffing to keep up with the student . . .