"Ow!" said Chelsie. "Stop that!" She looked behind her. Nothing. She looked over her other shoulder. The long, dark corridor was empty. Nothing moved in the gloomy old house. But someone - or something - had definitely touched her behind. Alarmed, she scuttled back to her room and shut the door. To her frustration she saw that although there was a large, gaping keyhole, no key was to be seen. She had heard that in the nin...