It’s all a simple trick.

“Mrs Van Rydock moved a little back from the mirror and sighed.”

After arriving back from Egypt, I whipped quickly into Lemony Snicket’s Series of Unfortunate Events (I’m re-reading the series this year, but not reviewing them) and then had another urge to read some more Christie. Normally, I can’t read the same author more than once in close succession – I get what I’ve termed “author fatigue”. That, and I mix things up. And so enter They Do It With Mirrors, the curiously titled Miss Marple mystery, of which I own a beautiful, purple hardback copy.

The title seems to have little to do with the events, until a chance comment by one of the policemen sets the final ball rolling. But I’m getting ahead of myself.

In this Christie, we follow Miss Marple to Stonygates, an old Victorian manor house that is falling apart and has never been modernised, when her good friend Ruth Van Rydock believes that her sister, Carrie Louise, is in danger. Although she cannot explain why she thinks this, she is adamant. Miss Marple is an old friend to both sisters and so sets off for what she claims is an innocent reunion with a school friend.

At the house, tensions are a little frayed. Carrie Louise’s granddaughter, Gina, has returned to England with her new husband, the sullen and grouchy Wally Hudd. Carrie Louise’s own daughter and Gina’s aunt, Mildred is sniffing around, and then there’s Carrie’s adopted sons Steve and Alexis, her doting husband Lewis Serracold, her bossy companion Jolly, and the completely unexpected arrival of her stepson, Christian Gulbrandsen. Oh, and then there’s the schizophrenic Edgar Lawson. Yes, that’s the other thing worth noting about Stonygates – old house it may be, but it’s also home to a whole raft of psychologists and their patients.

One evening, there is a ruckus in the great hall. Edgar Lawson bursts in with a gun and demands the truth – Lewis Serracold is his father! He always knew it, why wasn’t he told? However, Lawson is unbalanced – he often has delusions that his father is Winston Churchill or Viscount Montgomery. Determined to calm him down, Lewis takes him into his study and the two have a heated argument. Two shots are fired, but when the door is opened … both Lawson and Lewis are unharmed.

Upstairs, however, Christian Gulbrandsen lies dead.

The house is thrown into turmoil as everyone begins to suspect one another of murdering Christian – the only trouble is that no one seems to have a motive. And then things become even more convoluted when it turns out that Carrie Louise has been being poisoned.

Naturally, I was wrong in guessing whodunnit, as it always the case with Christie, but I was pleased to have worked out at least half of the solution. The true murderer was barely suspected by me, and I was all set on another, but nope, once more Dame Agatha and Jane Marple whipped the carpet out from under me with a magician’s flourish. Adding the twist of numerous people with mental illnesses in close proximity gives the whole thing a nasty turn – how can you find out the truth when absolutely anyone could be lying, and maybe not even know that they are?

Reality and illusion become twisted together in this ingenious novel which is sure to leave you maddened, but ultimately satisfied. After all, as one of the psychologists says, “We’re all a little mad.”