I am fairly sure I have never read They Do It With Mirrors before, but as I recently watched a TV adaptation, it was difficult for me to judge how easy it would have been to predict the outcome. I suspect it wouldn’t be.
Jane Marple has not seen her old school friend Carrie Louise for many years, but their mutual friend Ruth thinks something is not right, so she asks Jane to visit if invited. Carrie Louise is a frail woman whom others yearn to protect. She was left with a fortune after the death of her first husband. Her second husband left her for a dancer. Her third husband, Lewis Serrocold, is using wings of her massive home as a rehabilitation center for young criminals.
When Jane arrives, she finds quite a few people residing in or visiting the main house. Carrie Louise’s granddaughter Gina is there with her American husband Walter. Carrie Louise’s daughter Mildred is widowed and living there. Alex and Stephen, the two sons of Carrie Louise’s second husband, are there (well, Alex soon arrives on a visit), and they all get a surprise visit from Christian Gulbrandsen, an executor of the estate trust and Carrie Louise’s stepson. He is there to talk to Lewis, who is momentarily away, but Miss Marple sees them conferring outside when Lewis returns home.
After dinner, Christian has gone to his room to write letters when one of the inmates, Edgar Lawson, strikes up an argument with Lewis Serrocold and starts flashing a gun around. Edgar sometimes says different important men are his father and has moments of confusion and paranoia. This time he says Serrocold is his father and has been spying on him. The two go into his office, from which the others can hear the argument. They hear a gun fired outside, and then the gun in the office is fired, but when they get into the office, both men are fine. Later, though, Christian Gulbrandsen is found shot to death.
When questioned by the police, Lewis tells them Christian suspected Carrie Louise was being poisoned, her arthritis symptoms being similar to slow arsenic poisoning. And sure enough, when the police check a bottle of tonic that Serrocold told her not to take, it’s poisoned.
Soon there are two more deaths, and insights are needed from Miss Marple.
There are a lot of characters in this story and perhaps they’re not as vivid as Christie’s usually are, but she has set us an entertaining puzzle to solve.