Mollie Davidson

In the unpublished short story The Incident of the Dog's Ball, Mollie Davidson was the niece of Matilda Wheeler. She was unmarried and worked in a beaty parlour in Dover Street, London but made regular trips to visit her aunt at Little Hemel in Kent.

Mollie was one of the benficiaries of her aunt's will. However, after Miss Wheeler had an accident and fell down the stairs, she decided to make a new will which disinherited Mollie and her other relative, her nephew James Graham. Shortly thereafter, she died.

Investigations by Poirot revealed that Miss Wheeler had shown the new will to James but not to Mollie. Mollie was surprised that James knew about the new will but had not told her about it. In the end, Poirot in the end exonerated James largely because he lacked a motive and his suspicion centred on Mollie. His conclusion was supported by a trick he played on Mollie. During an interview with Mollie, Poirot "accidentally" had a rubber ball drop out of his pocket. Mollie immediately associated it with a dog's toy and asked Poirot whether he kept a dog.

Poirot wrote to Mollie with a full account of how he believed she had killed her aunt and hinted that an exhumation of her aunt would be applied for. Two days later, the newspapers published an account that Mollie had died from an overdose of a sleeping draught.

Agatha Christie's Notebook 66 contained brief sketches of the characters Christie was planning for the story. Here, she planned Mollie to have a young man who was a "ne'er do well" but in the end he did not feature in the story.

When Agatha Christie later expanded into the short story into the full length novel Dumb Witness, Mollie's role was split between two characters, both nieces od the rich aunt. One was the unmarried Theresa Arundell and the married Bella Tanios. The latter was the killer and she committed suicide in the same way after Poirot revealed her methods to her in a letter.