Miss Gilchrist

"But he was murdered, was he?"

- Miss Gilchrist, while disguising as Cora Lansquenet

"She was a thoroughly stupid woman! Endlessly wittering on about this place and what you all did as children. You don't know how truly stultifying it is to listen to someone talking about the same things day after day, and pretending to be interested. "Oh, yes, Mrs. Gallaccio," and "Really, Mrs. Gallaccio?" And in truth just bored, bored, bored! And nothing to look forward to but more of the same."

- Miss Gilchrist revealing her true colors (in TV series)

Miss Gilchrist is the main antagonist of Agatha Christe's 1953 Hercule Poirot novel, After The Funeral. She is the paid companion of the story's victim, the eccentric Cora Lansquenet (Cora Gallaccio in Agatha Christie's Poirot), whom she killed in order to steal a piece of Vermeer painting from her collections.

It was revealed in the climax that prior to the murder, Miss Gilchrist disguised as Cora and attended Richard Abernathie's funeral, spreading the rumors of Richard being murdered and caused the family's paranoia, so that she could have a chance to gain Cora's collection of Vermeer for herself.

In Agatha Christie's Poirot, she was portrayed by Monica Dolan, who also portrayed the real Cora Lansquenet.

Overview
Miss Gilchrist was orginally Cora Lansquenet's paid companion, who was misused by the Abernathie heirs and despised her as a result of that. One day, she saw what Cora had missed among the paintings that Cora had bought at the local sales. Miss Gilchrist felt sure one was a painting by Vermeer. However, Cora was ignorant of how valuable the artwork was. Enraged and desperate, Miss Gilchrist had to kill Cora to gain the painting for herself. Her dream was to sell the Vermeer to escape her dreary life with the capital to rebuild her beloved teashop, "the essence of gentility", lost during the war to food shortages.

The painting's value would likely have been revealed to Cora when her friend the art critic visited, explaining in part the timing of the murder. Miss Gilchrist covered the Vermeer with her own painting depicting the destroyed pier copied from the postcard, to disguise it amongst others done by Cora. The scent of the oils lingered when Mr. Entwhistle visited the cottage the day after Cora's murder.

Afterwards, Miss Gilchrist put a sedative in Cora's tea so she would be asleep, while Gilchrist posed as Cora at the funeral. None of the family had seen Cora for more than two decades and did not recogized the imposter. After the funeral of Richard, "Cora" intentionally spoke out that Richard was murdered in order to cause unease. To cement such unease, Gilchrist killed Cora the following day so that police would believe it was connected to Richard's death. To divert suspicion from herself, Gilchrist faked the attempt on her life by eating a poisoned chocolate cake prepared for herself, but in a proper amount so that the toxin would be surmountable.

However, while Gilchrist made her best to copy Cora's characteristic turn of her head, she had made the wrong direction because she rehersed it in front of a mirror. Helen was attacked because she eventually realised this. The Vermeer was hidden by Gilchrist so that Guthrie did not find it during his scheduled visit.

During the investigation, Poirot discovered that Miss Gilchrist had posed as Cora because she made a reference to a piece of decoration, named the Wax Flower Bouquet, which could only have been seen within Enderby Hall on the day of Richard's funeral. It became the crucial evidence to reveal that "Cora" who attended the funeral was an imposter.

Once accused and exposed, Gilchrist broke down and ranted about the hardships of her life, but she soon accept her arrest by the police. During legal proceedings before her trial, Entwhistle informed Poirot that Miss Gilchrist eventually turned insane, in a relentless fervor of planning one tea shop after another. Nevertheless, Poirot and Entwhistle have no doubt she was in full possession of her faculties during her crime.