How well do you know your neighbour? Lexie and Harriet live next door to each other in an upmarket block of flats in London, but never speak. It’s not as though they dislike each other, it’s just not the done thing. The thought of bumping into each other in the lift abhors them and yet they happily eavesdrop on each other through their paper-thin walls. With both women experiencing problems in their personal lives, they soon begin to covet each other’s life with dangerous consequences…

With its slow build-up, Through the Wall is one of those books that takes you a while, but once it’s grabbed you, there’s no letting go! From its opening in a psychiatric hospital, there is a air of foreboding where you know that something bad is about to happen, but what?

From the outside, Harriet looks like the ultimate party girl, her raucous gatherings drawing in strangers from near and far. Lexie wouldn’t be as jealous, however, if she knew Harriet’s past and that this was one way of hiding her loneliness. Similarly, Lexie looks like she shares the perfect life with her husband, Tom, the sort of life that Harriet dreams of. Her happy social media posts hide the trauma of losing a child, though, and do not take into account the pain of trying for a baby. This was a good lesson in how we should not always believe what people choose to share on the likes of Instagram or Facebook, as these posts often display a skewed version of the person’s real life.

Throughout the book, we see Harriet’s interest becoming more and more of an obsession, to the point where she is stalking both Lexie and Tom, even gaining access to their property. I began to fear for Lexie as Harriet became fixated with Tom, wondering just how far she would go to achieve her aim. At the same time, I had nothing but sympathy for Lexie as she began her IVF journey, believing at the same time that her husband was having an affair with a woman called Rachel.

Just when I thought that Harriet had no redeeming qualities whatsoever, the author hit me with details of her past, exploring how she had been the victim of an abusive ex-partner, even if she was in complete denial about this. At this point, I was desperate for someone to take Harriet into their care, to stop her from hurting someone else or even herself. The fears for Lexie were still there, however, and were proven correct when we finally get to the showdown between the two women. The tension was palpable as I began to wonder if history was about to repeat itself.

The story ends where it begins – at the psychological hospital, and it is here where we get the twist that made me gasp. This was one of those moments where you can visualise it on the screen, and I hope that this is something we get to see at some point.

Through the Wall is a disturbing psychological thriller with some genuinely emotional moments. With thanks to Avon Books UK and to Sabah Khan for organising the blog tour.