Alan Carr investigates his favorite Agatha Christie character, the inimitable detective Hercule Poirot. Visiting locations across London and Devon, Alan gets to step literally into Poirot's shoes as he gets kitted out in his original suit, learns the secret of recreating that memorable walk and finds out just what makes the perfect Poirot moustache. Later, Alan "takes part" in a performance of Witness For The Prosecution.