Agatha Christie's most daring crime mystery - an early and particularly brilliant outing of Hercule Poirot, 'The Murder of Roger Ackroyd', with its legendary twist, changed the detective fiction genre for ever.Poor Roger Ackroyd. He knew the woman he loved had been harbouring guilty secret. And then, yesterday, she killed herself.But guilty secrets rarely stay secret. Who had been blackmailing her? Had it really driven her to suicide? Sadly, Roger Ackroyd wasn't going to live long enough to find out ...