The Tunnel Tigers were an elite group of construction workers who specialised in a lucrative but hazardous profession – blasting tunnels through mountains and under rivers, in dangerous conditions few men could endure.

Alice Larkin, the headstrong daughter of a millionaire and former news reporter, claims her lover, a Tunnel Tiger, died in mysterious circumstances many years ago, and she wants journalist Rebecca Connolly to investigate.

Intrigued, Rebecca throws herself into investigating the story, but she soon comes face to face with an old adversary. Family legacies and influential reputations are at stake – and danger is shockingly close to home.