Who can we turn to, if justice betrays us? 1930. A chilling encounter on London's Necropolis Railway leads to murder. At the Old Bailey, a man accused of a "blazing car" killing escapes the gallows after a surprise witness give sensational evidence. And journalist Jacob Flint finds himself framed for murder. To save himself, Jacob needs to discover what links these strange events to a remote estate on a northern coast, Mortmain Hall. There, an eccentric female criminologist hosts a gathering of people who have narrowly escaped the consequences of miscarriages of justice. But the house party culminates in tragedy when a body is found beneath the crumbling cliffs. Is the death an accident, or the result of an ingenious plot to get away with murder? Rachel Savernake, who's been invited to the party, proposes an intricate-and dangerous-solution to the assembled guests, having done her own sleuthing into the labyrinthine secrets of Mortmain Hall. Will her relentless quest for the truth bring down the British establishment?