Lois Hargreaves

In the short story The House of Lurking Death, Lois Hargreaves was a young woman who contacted Tommy and Tuppence after a mysterious poisoning episode at her household at Thurnly Grange. She did not want to approach the police and wanted the whole matter dealt privately because she suspected a member of her own household.

After hearing her account of the poisoning and her family background, Tommy and Tuppence believed there to be a murder plot against Lois. Lois had inherited a large amount of wealth from her aunt Lady Lucy Radclyffe. This was a surprise to Lois as there was a closer relative, a nephew Dennis Radclyffe. Lady Radclyffe had always indicated that he would inherit the bulk of the estate but it seemed she had cut him off after a disagreement. In any case, Lois then made a will leaving everything to Dennis in the event of her death. This will had been made as soon as she turned twenty-one, just three weeks before the events in the story. In view of the urgency, Tommy and Tuppence decided to rush down to Thurnly Grange the next day but were too late, as several members of the household died from poisoning that day including Lois.

Tommy describes Lois as "like those girls Mason writes about ... frightfully sympathetic, and beautiful, and distinctly intelligent without being too saucy."