Istanbul, 1926 After her historian father makes a clandestine journey abroad, Jane and the dapper Mr. Redvers trace his footsteps while signs of danger loom back home in the United States. They're greeted at their destination by Aunt Millie and unsettling news: Professor Wunderly was on a mission to locate the lost heart of Sultan Suleiman the Magnificent--a legendary relic from the Ottoman Empire said to possess potent mystical powers--then vanished completely, leaving behind his unpacked luggage, a perplexing riddle, and an eerie mystery Jane must solve to keep her loved ones safe.

What starts off as a clear-cut investigation becomes an intercontinental game of cat and mouse as Jane realizes a gang of nameless figures have been stalking her every move from Turkey to Hungary. And it seems even helpful friends can't be trusted for long when a man is stabbed to death on the Orient Express to Budapest. With Redvers by her side and few clues to rely on, Jane's desperate search for her father leads to centuries-old secrets and an unidentified enemy who could make her disappear like the missing Sultan's heart . . .