I like to refer to Louise Candlish’s particularly engaging style of psychological thriller as “real estate thrillers”. I say this, of course, with a bit of a wink. I’ve referred to them before as “neighborhood noir” as well, and this is probably the more conventional subgenre, but it seems like there is a bit more to it. Now that I’ve read a half-dozen books by her, there is always a piece of real estate heavily involved in the escalation within the plot. In The Other Passenger, it that real estate is the house that caused a thousand tiny fractures in a relationship and led to the other events. Another must-read psychological thriller from Louise Candlish!The CharactersJamie is our narrator and he is married to Clare. Jamie and Clare are around the age of 50, and have been married for years. While Clare is successful and has family money, she never holds that over Jamie’s head. But it does frustrate her a bit that Jamie just doesn’t care about working. In fact, he actively evades her offers to help him find a new career path or fund retraining, and privately he holds all of this over her head. She’s also the owner of their house, which bothers Jamie though Clare is kind-hearted and happy to share what is hers with her husband.Melia is a new junior colleague of Clare’s at her firm and she is married to Kit. Melia and Kit are younger than Jamie and Clare, around the age of 30. And Melia is stunningly beautiful, while Kit is a gregarious sort. Both are wannabe actors forced into other professions. At first the two couples become fast friends, despite their obvious gap in age and wealth. As the book picks up, the barbs from Kit towards Jamie about being a tenant in their own home begin to fester.The PlotJamie seems to have a great life. He is married to Clare, who has family wealth and has bought them a beautiful home. Their marriage is a happy one. Sure, they are now 50 and don’t have the excitement of people in their 20s. But overall things are good. Jamie suffers from claustrophobia which makes train commuting difficult. But in a brilliant move, he now has a group of friends who call themselves the “river rats” and take the water taxi to work.Until one of his friends Kit goes missing around Christmas. Kit is the husband to Clare’s coworker Melia, and the couple is young, attractive, and fun. What started as a great friendship between the two couples has spiraled. Melia reports Kit missing and when Jamie departs the river taxi, he is stopped by two police officers. They have heard that the night Kit went missing, Kit and Jamie were in a heated argument on the river taxi. Who is the other passenger that reported it? Surely Jamie won’t go down for a crime he didn’t commit… right?Overall ThoughtsJust when you think you know where this book is headed, think again! The Other Passenger by Louise Candlish totally blew me away. There are layers here, the first and most important being the relationship between the four main characters and central couples, Jamie, Clare, Kit, and Melia. Jamie and Kit seem both drawn to one another as friends and kindred spirits, separated by two decades, and equally explosive. It felt that their friendship was just a ticking bomb waiting to blow up.Kit judges Jamie (while also admiring him) for having fallen into a marriage that gives Jamie the lifestyle Kit wants. Jamie works in a coffee shop, so not exactly a career, and he lives in a huge and beautiful piece of real estate that most in London can only dream of. Clare is a supportive wife. Sure, she wants Jamie to have a bit more ambition, but not because she cares how much money he makes. It is because she wants him to be fulfilled and he clearly isn’t.Meanwhile Jamie covets Kit’s life—he is young, attractive, and married to the beguiling Melia. Melia is stunningly gorgeous and alluring. Jamie can’t not notice it. But he is happy with Clare, isn’t he? Why would Jamie do anything to jeopardize the great life he has?The dynamic between Clare and Jamie fascinated me. Clare is so inherently good—but at the same time there is an element Candlish hints at (without ever outright saying) where the reader understands that Clare is able to be that way because of her privilege. It is easy to have a simple and kind life when money isn’t a worry. Jamie feels that he is beholden to Clare because of that, and over the course of the novel what should be a small insecurity over their power imbalance grows into something much more substantial.Jamie resents Clare. He knows that if their relationship goes south, he will be left out of the wonderful life he has with Clare. He is a visitor to this life, but not a resident in it. His visa is temporary and could be taken away in the blink of an eye. This makes it all the more compelling when he seems to intentionally engage in actions that could jeopardize the very thing that makes his life so enviable.I think it is easy to feel for both Jamie and Clare in different ways while reading this book, and to roll your eyes at Kit and Melia. In a way, Kit and Melia also have things that others covet. They are young, beautiful, charismatic, dynamic, and engaging. Everyone wants to be around them. And these qualities mean they have an advantage towards being successful if they want to. But similar to Jamie, Kit seems to be a saboteur of his own life. The two constantly seem one chapter away from blowing up their lives, or perhaps their friendship.A compelling and sharp psychological thriller that had me tense through the very final page!