Laura Ruby

When Frankie's mother died and her father left her and her siblings at an orphanage in Chicago, it was supposed to be only temporary - just long enough for him to get back on his feet and be able to provide for them once again. That's why she is not prepared for the day that he arrives for his weekend visit with a new woman on his arm and out-of-state train tickets in his pocket. Now Frankie and her sister, Toni, are abandoned alongside so many other...

"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...

In an alternate history of New York, three kids try to solve a modern-world puzzle and complete a treasure hunt laid into the streets and buildings of the city.