Through a glass, darkly

Art teacher Faustina Crayle is drab, retiring and quiet; yet there's something about her that unsettles the students and staff at the posh girls' schools where she has been teaching, to the point where she's just lost her second job in a row. Before police psychologist Basil Willing can get to the bottom of things, another teacher is dead -- murdered. Eyewitnesses put Faustina at the scene of the crime and, at the same time, in a respectable working womens' hostel miles away. Is she an innocent victim or a very clever murderess?