[CRussel]

Well, while I like the idea of another Peter Grant, I also think it's past time we read a Ngaio Marsh mystery. We could start at the beginning, with A Man Lay Dead, but I'd rather start at the first of the series that includes an important new character, Agatha Troy, so instead, I'll nominate Artists in Crime.
Goodreads:

Spoiler:

It was a bizarre pose for beautiful model Sonia Gluck--and her last. For in the draperies of her couch lay a fatal dagger, and behind her murder lies all the intrigue and acid-etched temperament of an artist's colony. Called in to investigate, Scotland Yard's Inspector Roderick Alleyn finds his own passions unexpectedly stirred by the fiesty painter Agatha Troy--brilliant artist and suspected murderess. First published in 1938.

Amazon:

Spoiler:

In the movies, it’s known as a “meet cute.” But for Inspector Alleyn and Miss Agatha Troy, it’s more like irritation: On the ship back to England, she finds him tedious and dull; he thinks she’s a bohemian cliché. They may be destined for romance, but there’s a murder in the way: No sooner has Alleyn settled in to his mother’s house, eager for a relaxing end to his vacation, then he gets a call that a model has been stabbed at the artists’ community down the road. And the artistic Miss Troy is one of the community’s most prominent and outspoken members.

AmazonUS: $7.99
AmazonCA: $9.99 CDN
AmazonCA 3 Book Collection: $11.99 CDN
Audible (Nadia May Narration): $19.57
KoboCA: $11.99 CDN (3book) $9.99 CDN (Single)