A murder without motive. A downtown bombing. The sins of the past revisited... DI Nathaniel Caslin is heading up a specialist unit, an opportunity to make a real difference. Little does he know, decisions taken decades previously are about to threaten all that he holds dear... Gangland tensions are on the rise as an uneasy peace is fractured in spectacular fashion. Two warring factions are lining up to unseat the other. Old adversaries rekindle their passion to exact revenge whilst the next generation seek to make a name for themselves. Meanwhile, Caslin is asked to investigate the mysterious murder of a private detective, revealing the vested interests of a multitude of figures. Finding himself walking the line between upholding the law and delivering justice, Caslin sees the past returning to haunt those around him. A crime perpetrated years previously sends ripples far and wide. Some people have much to gain whilst others have so much to lose... none more so than Caslin himself...