In the short story At the 'Bells and Motley', Mary Jones is the daughter of the landlord of the Bells and Motley in Kirklington Mallet.
Mary's father would not allow her to marry Stephen Grant. Stephen had been implicated in the disappearance of Captain Harwell. Nothing could be proven against Stephen and the police seemed to be satisfied as to his innocence. However, the villagers, including Mary's father, continued to look at Stephen with suspicion. As Mary's father put it, "I've nothing against Stephen, but - well, we don't know, do we?" As Mary tells Mr Satterthwaite and Harley Quin, the true facts about Captain Harwell's disappearance had to be established. Nothing else could help Stephen. Mary's plight attracted the sympathy of Mr Satterthwaite and motivates him to solve the case. How he does this with the help of Mr Quin forms the main plot of the story.