In this psychological thriller, the story revolves around a troubled woman who becomes entangled in a missing persons investigation that promises to send shockwaves throughout her life. As she rides the train every day, she fantasizes about the seemingly perfect couple she sees from her window, until one day she witnesses something shocking in their backyard. Her decision to report it to the authorities leads her down a dark path of intrigue, as she struggles to piece together her fragmented memories and the tangled web of lies, deceit, and complicated relationships that surround the case. Her involvement becomes increasingly dangerous as she tries to prove not only what she saw, but also her own worth and sanity.

In "The Turn of the Key" by Ruth Ware, a young woman named Rowan Caine takes a job as a live-in nanny at a luxurious smart home in the Scottish Highlands. However, the seemingly perfect opportunity quickly turns into a nightmare as Rowan discovers the dark secrets hidden within the house and the tragic events that have unfolded in the past. As strange occurrences escalate and tensions rise, Rowan becomes the prime suspect in a murder investigation, desperately trying to prove her innocence and uncover the truth before it's too late.

A reclusive writer receives an unexpected invitation to a bachelorette party of an old friend she hasn't seen in years. Curiosity gets the best of her, and she attends the gathering at a secluded cabin in the woods. As the weekend unfolds, tensions rise and secrets are revealed, leading to a shocking and tragic event that leaves the protagonist questioning her own sanity and the motives of those around her.

The novel centers around Hope Arden, a woman who is afflicted with a peculiar condition that makes her unmemorable to everyone she encounters, effectively rendering her invisible in society. Despite her unique challenge, Hope becomes a master thief, capitalizing on her ability to slip through the cracks of people's consciousness. Her life takes a dramatic turn when she steals a piece of jewelry that ties her to a sinister technology company with a global influence. As she delves deeper into the company's operations, she uncovers a conspiracy that threatens her anonymity and the very fabric of her existence, leading her on a journey that challenges the nature of identity, memory, and what it means to be truly seen.