Can London's most elusive killer elude the keen minds of Scotland Yard's most unlikely pair of detectives? An Irish redhead of humble beginnings and modest means, Kathleen Doyle is the antithesis of Chief Inspector Michael Sinclair, Lord Acton, the brilliant but enigmatic lord with a knack for solving London's most high profile homicides. When a horse trainer is found dead at a racetrack, the duo's investigation does little to deter the killer at large. Jeopardizing the case are their colleagues at CID headquarters, whose nosing into the nature of Doyle and Acton's after hours relationship threatens to lay bare the most classified information of all. As the murders pile up, Doyle and Acton uncover something far more sinisiter than they could have imagined. Now that they know too much, their partnership could be very brief indeed. . .