She’d always had what her parents called “a prodigious imagination,” but she never could have imagined what had transpired over the summer. The fact that all five original Morningstarr buildings would be sold to Darnell Slant didn’t surprise her at all; she’d been worried about that since she was little. But she didn’t anticipate the fact that her grandfather would be sent a clue to the Morningstarr Cipher that no one had ever seen before. Or that the letter would lead to a whole new set of clues, a sort of shadow cipher operating independently from the original, a shadow cipher that Tess was convinced was the real Cipher. Or that solving the clues in the shadow cipher would lead to a horrible betrayal on the part of one of her grandfather’s oldest friends and the destruction of the Morningstarr building they were trying so hard to save. The fact that Theo and Tess would be forced to live with their great-aunt Esther in Queens and Jaime with his grandmother in a brand-new building all the way in Hoboken, New Jersey. The fact that they had no idea where else the Cipher would take them. The fact that solving the clues seemed to have awakened something at the very heart of the city itself, something that Tess wanted to trust, but . . .

Nine mrrowed again, rubbed her big face against Tess’s leg.

“My thumb is going numb,” said Theo.

“I’ll take a turn,” said Tess. She and Jaime switched so that Jaime was trying the combinations on the lock and Tess was keeping track. Theo sat on the step scratching Nine’s ears until her purr was a soothing rumble. When Jaime’s thumb went numb, Tess took over trying combinations and Theo took notes. Jaime sat on the steps to rest, and Nine licked his knees.

They switched places, and switched again. Hours went by. Or days. Tess couldn’t be sure.

Jaime flexed his fingers, rolled his wrist. “What if it’s a number we know already?”

Their old building was 354 W. 73rd Street. Perking up, Tess said, “Try three-five-four!”

Jaime did. No luck. They also had no luck with other addresses, birthdays of the Morningstarrs, or the month and the day the Morningstarrs disappeared.

“Let’s just keep working,” said Theo. “We’ll get there.”

Jaime sighed, hefted the lock again. Then, he frowned, ran his thumb over the hasp.

“What?” said Tess.

“The hasp isn’t a loop, but it’s not straight, either.”

“Yeah, I noticed that,” said Tess.

“It looks like cat ears.”

“What?”

“The way a little kid would draw cat ears. Triangle, straight line, triangle. See?”

Nine mrrowed softly, wound herself around Jaime’s feet.

“A cat,” Theo repeated.

“Or a Cat,” Tess said. “Like Nine.”

“Or nine,” said Theo.