Ngaio Marsh was a prominent figure in the mystery genre, and her impact is still felt today. Here are some ways in which she influenced the genre:

1. Complex and dynamic characters: Marsh was known for creating more nuanced and complex characters than the typical one-dimensional characters found in many mystery novels of her time. Her feelings had backstories, personal flaws, and motivations that were explored in depth, which made them more relatable and exciting to readers.
2. Attention to detail: Marsh was known for her meticulous attention to detail in her descriptions of crime scenes and investigations. Her careful attention to detail helped to create a sense of realism and authenticity in her novels.
3. Rich settings: Marsh was also known for creating richly detailed environments that transported readers to different times and places. Her descriptions of the English countryside and the theatre world were particularly noteworthy and added depth and richness to her novels.
4. Use of language: Marsh was a gifted wordsmith, and her use of language was often praised for its beauty and clarity. She was exceptionally skilled at creating vivid and memorable descriptions of characters, settings, and events.
5. Inclusion of social commentary: Marsh often used her novels to explore social issues and cultural trends. Her stories tackled topics such as class, gender, and race, and her willingness to confront these issues helped to elevate the genre and make it more socially relevant.

Ngaio Marsh’s impact on the mystery genre was significant. Her attention to character, detail, language and social commentary helped to elevate the genre and make it more intellectually engaging and culturally relevant. Her influence can be seen in the works of many contemporary mystery writers, and her novels continue to be widely read and enjoyed today.