When Phoebe Griffin, still haunted by the horrors of her past, is unable to discover news of her friend; Quirke, fresh from drying out in an institution, responds to his daughter's request for help.
But as Phoebe, Quirke and Inspector Hackett speak with those who knew April, they begin to realise that there may have been more behind the young woman's discretion and secrecy than they could have imagined.
Why was April so estranged from her family, the Latimers: powerful figures within the city?
What is the close-knot circle of friends that both Phoebe and April belong to hiding?
And who is the shadowy figure who seems to be watching Phoebe's flat at night, through the frozen mists?