"Amy," he called down, "what were those four branches again"

"Ekaterina," she called. "Tomas, Janus, Lucian."

"Ekaterina," Dan repeated, as he pressed the E. "Tomas, Lucian, Janus."

As he pressed the last letter, the whole shelf swung outward. Dan had to jump away to avoid getting squished into a book sandwich.

Where the bookshelf had been was a dark stairwell, leading down.

"A secret passage," said Uncle Alistair. "Dan, I'm impressed."

"It might be dangerous!" Amy said.

"You're right," Dan agreed. "Ladies first."

CHAPTER 5

Amy could've lived in the secret library. Instead, she almost died there.

She led the way down the steps and gasped when she saw all the books. They went on forever. She used to think the main public library on Copley Square was the best in the world, but this was even better. It seemed more library-ish.

The shelves were dark wood, and the books were leather-bound and very old, with gilded titles on the spines. They looked like they'd been well-used over the centuries.

Oriental carpet covered the floor. Cushy chairs were spaced around the room so you could plop down anywhere and start reading. Maps and oversize folios were spread out on big tables. Against one wall was a line of oak file cabinets and a huge computer with three separate monitors, like something they'd use at NASA. Glass chandeliers hung from the vaulted ceiling and provided plenty of light, even though the room was obviously underground. They'd descended a long way to get here, and there were no windows.

"This place is amazing!" Amy ran into the room.

"Books," Dan said. "Yay." He checked out the computer, but it was frozen on the password screen. He jiggled a few file cabinet drawers, but they were all locked.

Uncle Alistair gingerly picked a red folio from the shelves. "Latin. Caesar's campaign in Gaul, copied on vellum. Looks like it was handwritten