Lady Nancy Astwell

In the short story The Under Dog, Lady Nancy Astwell is the wife of Sir Reuben Astwell.

After her husband was murdered and her husband's nephew Charles Leverson was arrested for the crime, she sends her companion Lily Margrave to request Poirot to look into the case. Lady Astwell had a firm belief in her own intuition which she says had always proven her right, and in this case, she has a firm intutition that Charles is innocent and that the secretary Owen Trefusis was the killer, although there are no facts to support this belief.

Poirot believes that Lady Astwell may have seen something but is not conscious of what she saw. With the help of Dr Cazalet, Lady Astwell is hypnotised and while under this state she describes a number of salient observations which would prove to have a bearing on the case: Lady Astwell had gone to the "tower room" or study of Sir Reuben where they had an argument about why he was sacking Lily Margrave. While there, she noticed a bulge in one of the curtains, suggesting someone was behind it. She was certain this was Trefusis because of an incident earlier in the evening. After dinner, Sir Reuben had angrily summoned Trefusis for some error he had made. The normally self-controlled Trrefusis was so overwrought that he plunged a paper knife into a table with such force that the tip broke off.

Lady Astwell, by her own admission is "not a lady" herself and she tells Poirot this is something that the servants know about. Her husband had also once dismissively told her that he had picked her up "from the gutter". She lacked education and had been an actress before her marriage. She brushed aside the significance of Lily Margrave's forged references. She said that she had done many worse things than that "in the old days". "You have got to be up to all sorts of tricks to get round theatrical managers. There is nothing I wouldn’t have written, or said, or done, in my time," she added.

Portrayals
In ITV's 1993 adaptation of the story, Lady Astwell is portrayed by Ann Bell. Here she had the same intuition that Charles Leverson was not guilty but did not appear to have an intuition that Trefusis was the killer. Her account under hypnosis is slightly different. There is no mention of having seen Trefusis break the paper knife. (In this adaptation, the broken knife is discovered by the maid Gladys.) Here Lady Astwell's only grounds for her belief in Charles' innocence was that in Sir Reuben's study she had seen a bulge in the curtain. She did not know who was behind the curtain, or perhaps she did not have time to say it when Poirot pressed her. In this adaptation, Lily Margrave interrupted the hynopsis and "woke" her before she could say who was behind the curtain.

During hynopsis, Lady Astwell also says that she and Victor Astwell loved each other very much. This added plot element served mainly to make both to be more plausible as suspects since here there were joint heirs to the estate of Sir Reuben. There is no mention in the adaptation of her low class background.