Your story draws us in with the story of the bears and the sense of danger and mystery around this school. We have a spine-tingling sense that an other-wordly presence is causing a disturbance in the library... perhaps the ghost of Mistress Zhara! Although I wished to learn the reason for Zhara's disappearance, I like the enigmatic way the story ends.
Martha is afraid. Again the whispering Martha.......Martha....... Martha....... Read..... read..... read..... read, there it is...... there it is........ there it is...........