The old boarding school stood on a mist-shrouded hill in northern India, a relic of a bygone era with its colonial-era architecture and stone-grey walls. For the children who lived within its hallowed halls, the corridors echoed with more than just the clamor of school bells and hurried footsteps; they whispered tales of the supernatural. The most enduring of these was the legend of "Chalk-wali Didi," the spirit of a teacher said to haunt the classrooms after dark.Ten-year-old Sameer, new to the disciplined life of the boarding school, found these stories to be nothing more than childish fantasies. His dormitory.......