Rachel Holloway is a school teacher with an unremarkable life. That is, until one day when everything changes forever and she is given the gift (or is it curse?) of being able to see and speak with the dead - amongst others... As she grapples with this strange new ability, she encounters many colourful characters, both living and dead. Some try to guide her, while others use her power for their own ends. When a girl is brutally murdered, Rachel is thrust further into a labyrinthine world of spirits that are trapped in a limbo state between earth and whatever lies beyond. She soon discovers that what lies in the shadows is legion and some things that exist in this dimension are far more evil than anyone could imagine.