A high-stakes game of survival unfolds in the rugged terrain of County Tyrone as an IRA informer becomes the target of a lethal manhunt. MI5 agents are tasked with the protection of a man whose life is the only thing standing between them and a intelligence failure, while IRA operatives mobilize to eliminate the threat he poses to their organization. The narrative follows the tense, claustrophobic movements of both the hunters and the hunted across the desolate Irish landscape. Through a third-person perspective, the story examines the cold, calculated mechanics of counter-insurgency and the brutal reality of paramilitary conflict.

This work is widely regarded as a quintessential example of the modern espionage thriller, noted for its gritty realism and lack of romanticized violence. Readers often highlight the author's ability to maintain suspense through technical detail rather than relying on sensationalist action sequences. The narrative structure effectively balances the perspectives of both the protectors and the pursuers, creating a sense of inevitable collision. It remains a significant entry in the genre for its unflinching look at the human cost of intelligence operations during a period of intense political instability.