Manda is driven to confronting her stalker on a lonely mountainside in Scotland.
But what brought her to this moment?
Manda is desolate when Gareth, her lover of ten years, leaves her for another woman.
He introduced her to bird-watching, a hobby which provides Manda with an escape from her troubled past.
But she is unsettled by the attentions of David, another twitcher.
David seems to know more about Manda than he ought to and his attentions are becoming unsettling
Someone is hacking into Manda's computer and David is stepping up the harassment.
When Tom invites Manda down to Kent to check out the sighting of a firecrest, it seems a perfect escape.
Events in Manda's life take a sinister turn and memories of her troubled childhood return to haunt her.
The university gives her time off work on condition that she seeks help for her depression.
Manda's life is unravelling, and she goes to her favourite haunt to clear her head.
But someone else has got there first.
When she sees someone moving about in her house Manda flees and takes refuge at Tom's cottage in the woods.
From there she plans a new start, but will she choose safety or freedom?
When Manda reaches Norfolk her van becomes the focus of renewed and furious attacks.
Driving north - or driven north - she hopes to regroup in Scotland.
David is dead, but how will the police react given Manda's history? Should she run or should she hide?
The discovery of new evidence relating to David's death provides the last piece of the puzzle, and Manda tries to save Zannah before it is too late.