In this episode, Dawn French plays the Granny who comes to live with her daughter's dysfunctional family. The selfish daughter and her husband decide to "off" Granny who overhears the plot. Unknown to the daughter, Granny has the grandkids on her side. The three of them decide to go on an outing and Granny's bad habit of leaving the gas on when boiling eggs and daughter's bad habit of smoking in bed combine to form a Murder Most Horrid.