I've seen Millar described as the best mystery writer no ones ever heard of, which is probably true as she does not get the credit she deserves. Her husband was Kenneth Millar, aka Ross MacDonald who wrote the outstanding Lew Archer series, but the more I read of Millar the more I think she had the win in the writing stakes.
This is an outstanding mystery. As usual for her very dark ,but there is some funny dialogue from the PI hired to solve a wife disappearing.
There are not many of her 27 novels in print so if you're into the genre troll the secondhand stores and websites.
Highly recommended