When four-year-old Alfie vanishes during a community sports day, Detective Sergeant Darcy Doyle and Detective Inspector Mick Kelly are drawn into a case that grips Dublin with fear.
What begins as a desperate search soon darkens when a body is found in the Dublin Mountains - but the truth proves far more complex than anyone expects.
As media pressure intensifies and leads collapse, Darcy must navigate a web of lies, fractured families and shifting suspects, where every assumption threatens to derail the investigation.
At the same time, a ruthless crime boss launches a violent campaign of revenge that leaves a trail of blood across the city.
As both cases collide, Darcy and Mick race to uncover the truth - before time runs out and more lives are lost.