When a homeless man is found murdered in picturesque Lincoln, Northolme-based DS Catherine Bishop is drafted in to infiltrate Phoenix House, the shelter where 'Mackie' occasionally spent the night.

Working undercover with a new team is tough enough, especially as Catherine is still dealing with the emotional fallout from a previous case, but when someone close to her is critically injured in what may or may not be a related attack, the stakes are even higher.

Everyone who knew Mackie seems to have something to hide. How do you catch a killer when no one is willing to talk?