Elizabeth Cole and Margaret Litchfield

Elizabeth Cole and Margaret Litchfield are sisters divided by the belief that Margaret killed their father. That belief has become part of Elizabeth’s account of herself: she fears that her family history makes marriage and a future life impossible. Poirot’s final message overturns the accusation, identifying Stephen Norton, not Margaret, as their father’s killer, and asks Arthur Hastings to restore the truth to Elizabeth.

Sisters and the inherited accusation

Elizabeth’s distress emerges when Hastings tries to reassure her about another person’s kindness. She rebukes him as cruel and blind, then explains what stands between her and the thought of marriage: her sister is, in Elizabeth’s view, either a murderess or insane, and she cannot decide which possibility is worse. The accusation is therefore not merely a judgment about Margaret. Elizabeth experiences it as a burden attached to her own history and as a reason to doubt whether she may enter a future relationship.

The way Elizabeth states the dilemma leaves Margaret’s condition unresolved in her mind. She does not claim certainty about whether her sister committed the crime or was mentally unwell; either explanation, she says, has made marriage difficult even to contemplate. The sisters’ bond is thus marked by a painful uncertainty in which Elizabeth’s concern for Margaret coexists with the apparent necessity of treating her as morally or mentally compromised.

The remembered words

Hastings counters Elizabeth’s conclusion by recalling something she had told him before: “It wasn’t Maggie.” The remembered phrase gives their exchange a turning point. Elizabeth’s present certainty that the accusation is true meets her own earlier rejection of it, a fragment of speech that Hastings can now use to challenge the story she has come to live by.

When Hastings says directly that Margaret did not kill their father, Elizabeth stares at him, raises a hand to her mouth, and asks who told him. Her response marks the gap between what she has been carrying and what she can yet accept. The exchange does not show an immediate reconciliation between the sisters; it shows Elizabeth confronted with the possibility that her defining account of Margaret may be false.

The truth in Poirot’s message

Poirot’s final message supplies the explanation Hastings can offer. It identifies Margaret as innocent and says that her father was killed by Stephen Norton, whom the message describes as a sympathetic family friend and an “honest Iago.” This disclosure replaces the family accusation with a different account of the crime: the apparent friend, not the daughter blamed by Elizabeth, was responsible.

The message also connects the sisters’ story to Hastings’s own past. Poirot tells him to explain to Elizabeth that he, too, might have done what Margaret did, had no watchful Poirot been present. In that comparison, Margaret’s case is placed alongside Hastings’s susceptibility to another person’s influence; it is not presented as proof that the sisters shared a motive or acted together. Poirot’s point is that Elizabeth should not be left to judge Margaret under a false account of what happened.

What the revelation changes

Poirot specifically asks Hastings to find Elizabeth Cole, also known as Elizabeth Litchfield, and tell her what is in the message or let her read it. He frames this as a reason to free her from the belief that she is tainted by her sister’s supposed crime. The task makes the truth consequential beyond solving the father’s murder: it may allow Elizabeth to reconsider a future she has treated as unavailable.

The text closes the sisters’ account with disclosure rather than a narrated reunion. Poirot predicts that Elizabeth is still young and attractive and argues that she should not refuse life on the basis of a false belief; Hastings is left to carry the correction to her. Margaret’s innocence is established in the message, but the evidence does not show Elizabeth receiving it or the sisters reconciling. Their relationship ends, as represented here, at the threshold between a damaging accusation and the possibility of release from it.