The Murder of Roger Ackroyd
Clive Exton adapted seven novels and fourteen short stories for the series, including "The ABC Murders" and "The Murder of Roger Ackroyd", which received mixed reviews from critics. Anthony Horowitz was another prolific writer for the series, adapting three novels and nine short stories, while Nick Dear adapted six novels. Comedian and novelist Mark Gatiss wrote three episodes and also guest-starred in the series, as have Peter Flannery and Kevin Elyot. Ian Hallard, who co-wrote the screenplay for "The Big Four" with Mark Gatiss, appears in the episode and also "Hallowe'en Party", which was scripted by Gatiss alone.