“Yeah,” said Tess. “But we can’t go back in the daylight. Not if the clue means what I think it means.”

“That we have to dig up something next to Louis,” Jaime said. “I hope it’s not a grave. Please, please, please let us not have to dig up a grave.” He tossed a bit of hot dog bun to the enterprising squirrel, who chased the tumbling bit of bun to the base of a nearby tree.

A tree behind which two people in the most conspicuous trench coats that Tess had ever seen were trying to hide.

CHAPTER THIRTY

Theo

Tess gasped. Automatically, Theo gripped her arm. Jaime said, “Oh, sugar,” except he didn’t say sugar.

“What?” Theo said. “What is it?”

Jaime spoke out of one side of his mouth. “Two people hiding behind the tree. Three o’clock.”

“What people?”

“Not so loud!” Tess said, too loud.

The people hiding behind the tree tried in vain to make themselves smaller. It was the most inept display of spy craft that Theo had ever seen. Not that he was an expert on spy craft, but he assumed that if you didn’t want to be noticed, you shouldn’t wander around in knee-length trench coats on a ninety-five-degree day. Also, you shouldn’t try to hide behind a sapling.

“That’s just ridiculous,” Theo said.

“Shhh!” said Tess.

“It is pretty ridiculous,” Jaime said. “But don’t we know them?”

“Hard to tell with the giant sunglasses and the newspapers they’re holding up. Ono would be a better spy.”

“To the Land of Kings!” Ono burbled.

One of the spies dropped the newspaper for just a second. Tess gasped again, but this time in recognition.

“Omar Khayyám?” she said.

At the sound of his name, Omar Khayyám said, “Oh, sugar.” Except he really said the word sugar.

Then he said, “Forget it, Priya. We’ve been made.”

“Thank goodness!” said Priya. “I can finally take off this coat. It’s hotter than Hades is out here.”

“Hades isn’t hot,” Theo muttered. Tess gave him a look. “Well, it isn’t!”

“Hades isn’t real,” Jaime said.

“I know, I’m just . . . oh, never mind,” Theo said.

Priya Sharma and Omar Khayyám of the Cipherists Society, and old friends of the twins’ grandfather Ben, stripped off the giant sunglasses and coats and put the newspapers into the nearest recycling can for the Rollers. Sheepishly, they approached Theo, Tess, and Jaime.

“Sorry, kids,” said Priya. “We’re not so good at this. Not as good as the others.”

“Good at what?” Tess wanted to know. “And what others?”

Priya and Omar exchanged glances.

Jaime said, “Please tell us, Ms. Sharma and Mr. Khayyám. It’s been a really confusing day and I don’t think we can take any more confusion.”

“Your grandfather asked us to keep an eye on you three,” said Omar.

“But my grandfather is, he’s . . .”