Driving home in the rain, Cass decides to take a shortcut through the woods against her husband Matthew's wishes that she stick to the main roads. She is surprised to see another car on the road in such poor weather. She pulls in front of the car, but is too scared to get out thinking this may be a trap set to entice her out of her own vehicle. When the female driver does not approach, Cass figures help is on the way and drives off.
The next day, Cass hears on the news that the driver she passed was murdered. She is incredibly distraught and guilt-ridden thinking she could've done something. The guilt begins to eat away at her, especially after she learns the identity of the woman, and she was someone that Cass recently met. Her emotional state is smothering. On top of this, she is growing increasingly paranoid and forgetful—she is certain that she is suffering from early onset dementia, the same condition that her mother had—and therefore is not credible. She is convinced the murderer knows her identity and is responsible for the silent phone calls she has been receiving. But with her family history of dementia, and her mental state, who is going to believe her?
Paris brings nothing new to the realm of the suspense/thriller genre, in fact, there was nothing really that was overly shocking by way of plot twists, and Cass' inner dialogue was often repetitive. So why read this book? It is a page-turner and hooks you plain and simple. The novel is perfectly timed and flawlessly executed. Given the main character's paranoia and hysteria, the denouement could have been obvious and trite, but it wasn't because of the way she developed her unreliable narrator—this was the perfect angle from which to tell the story.