First published 1976.
Gilly Decker's second husband, Marco Decker, has been a human vegetable since suffering a stroke on their honeymoon. She spends her days attempting to communicate with him, and watching him die. Frightened of how alone she will be when Marco is dead, she hires a young lawyer, Tomas Aragon, to travel to Mexico in search of her first husband, B.J. Lockwood.
B.J. escaped to Mexico eight years earlier with Tula, Gilly's 15-year-old Mexican maid, and Gilly's brand-new motorhome. Tom (who is a great character, by the way, with shades of Highsmith's Tom Ripley about him, even though he is always definitely one of the good guys) quickly locates the small village where B.J. and Tula parked the motorhome, which the desert dust never allowed to leave again. He finds their son, physically and mentally handicapped, but no sign of the parents.
Keeping in regular contact with Gilly in Los Angeles, Tom follows a trail which leads him to the Quarry, a Mexican prison, and Harry Jenkins, a former business associate of B.J.'s. While he doesn't learn much, his enquiries must be helping someone, because everyone he tries to speak to about the whereabouts of B.J. is turning up dead.
This was Millar's fifth last novel, written when she was 61 years old. Like every other Millar novel I've read, this story gripped me right until the end. It's not that it's full of suspense and action and chilling murders, because it's not. Millar's novels are simply fantastic stories, very well told. This novel in particular revealed a shocking twist at the end so ingenious I never suspected it. 10/10