Olivia Williams as Agatha Christie

Anna Massey as Old Agatha Christie

Raymond Coulthard as Archie Christie

Stephen Boxer as Psychatrist

Anthony O'Donnell as Hercule Poirot

Anthony O'Donnell as Kenward

Mark Gatiss as Kenyon

Richard Leaf as Gunman

Bonnie Wright as Young Agatha Christie

Celia Montague as Agatha Christie's Mother

James Tucker as Reggie

Vicki Pepperdine as Carlo Fisher

Bertie Carvel as Max Mallowan

Edmund Kingsley as Soldier

Gregory Finnegan as Band Member

Toby Stephens as Doctor Edward Armstrong

Agatha Christie as Self (archive footage)