Johnny and Fergie are worried. Professor Childermass has been acting weird. Very weird. In this sixth Johnny Dixon mystery, the two boys sneak over to the professor's house to investigate, and what they find in the process is more amazing than usual: a talking statue, the ghosts of long‑dead Crusaders, and a rickety old trolley that turns out to be a time machine. Soon, our three heroes have traveled back to Constantinople in 1453. The Turks are invading and Professor Childermass has taken it upon himself to save the people trapped in the Church of Holy Wisdom. Johnny and Fergie must stop their friend from getting himself killed on his noble but doomed mission, but in doing so, do they risk their own lives? Will they all be lost in the past forever? "Spine tingling." -Publishers Weekly John Bellairs is beloved as a master of Gothic young adult novels and fantasies. His series about the adventures of Lewis Barnavelt and his uncle Jonathan, which includes The House with a Clock in Its Walls, is a classic. He also wrote a series of novels featuring the character Johnny Dixon. Among the titles in that series are The Curse of the Blue Figurine; The Mummy, The Will, and The Crypt; The Spell of the Sorcerer's Skull; and others. His solo novel The Face in the Frost is also regarded as a fantasy classic, and among his earlier works are St. Fidgeta and Other Parodies and The Pedant and the Shuffly. Bellairs was a prolific writer, publishing more than one dozen novels before his untimely death in 1991.