Police detective Alex Morrow is serving as a witness in arms dealer Michael Brown's trial, where the case hinges on his fingerprints found on the guns he sells. When the investigation leads to a privileged Scottish lawyer who's expecting to be assassinated after a money laundering scheme goes bad, and a woman who's spying on the people who put her in jail, Morrow has her hands full. And that's before she even gets to her family issues.
A lone robber bursts into a busy Glasgow post office carrying an AK-47. An elderly man helps the gunman fill bags with cash and is then murdered. DS Alex Morrow arrives on the scene. None of the employees can be linked to the gunman, and the grandfather is above reproach. As Morrow searches for the killer, it becomes chillingly clear that her involvement will go deeper than she ever could have imagined.