It was 1798 when the Morningstarr twins arrived in New York with a vision for a magnificent city: towering skyscrapers, dazzling machines, and winding train lines, all running on technology no one had ever seen before. Fifty-seven years later, the enigmatic architects disappeared, leaving behind for the people of New York the Old York Cipher -- a puzzle laid into the shining city they constructed, at the end of which was promised a treasure beyond...

It was only a few days ago that Tess Biedermann, Theo Biedermann, and Jaime Cruz, along with a mysterious figure from the past, managed to survive an assault on the location of the latest clue in the Morningstarr cipher -- and, in the process, made a shocking discovery about their own connection to this one-hundred-sixty-year-old enigma. Now the friends are divided. Tess and Theo have no idea what the photo they found in Greenwood Cemetery means,...