Snow is falling. An old woman reads alone in bed. There is the sound of breaking glass and footsteps on the stairs...Cambridge academic Cassandra James is shocked when her friend, Una, is found dead. It looks like a burglary gone wrong, but as more details emerge Cass begins to wonder. Why did Una try to ring her in the moments before she died? Why did she change her will and deprive the Cambridge Literary and Philosophical Institute of her library of Victorian literature? And that's not all that's troubling Cass. Strange things are happening at her daughter's nursery and who is this other Cassandra James running around Cambridge getting her in trouble? The line between appearance and reality begins to blur...