Emma Hedges' return to Dundee to start a new job brings her mother's unsolved murder into sharp focus as she fights to bring the killer to justice. However, before she makes the journey back to Dundee, a fatal fire in a nightclub proves an ominous omen.

As Kathy and Sarah work on their reports for the Secrets nightclub fire, the emerging picture is that two of the deaths were accidental, but the third victim was dead before the fire started. Sarah's report has some damning things to say about the safety of the building, but soon feeling overwhelmed by the police interest she wonders what she's started. Emma is cautioned by DI McKinven to stop sleuthing, as the stars align to put Daniel Macafee in her path - for whom she feels a deep connection. It later transpires that Daniel harbours a guilty conscience as he was employed by the company that refurbished Secrets.

McKinven's enquiries ruffle feathers and a furious Julie chides Emma for dragging up the past. When Emma is threatened with a knife, it's clear that someone's hiding something.

Daniel faces a culpable homicide charge for the fire and wants to protect Phil's reputation, but when Emma meets Phil for the first time, her instinct tells her to be wary of him.

Emma's accusation against Phil drives a wedge between her and Daniel. McKinven urges Emma to stop sleuthing, as he's certain that the person who killed her mother is known to her.

While Kathy oversees the excavation of Marie's grave, Daniel gives McKinven the lead he needs to make an arrest, but it's the exacting forensic science that finally brings peace for Emma.