Written by English author Stuart Turton and published in 2018, The 7 ½ Deaths of Evelyn Hardcastle is an unconventional mystery containing fantastic elements and science fiction themes. 

The story unfolds non-linearly through a central narrator, Aiden Bishop. Aiden finds himself trapped, reliving the same day time and again. However, each time he relives that day, it is from the perspective of a different guest or staff member at Blackheath House, a sprawling estate in the English countryside. 

Despite the detailed discussion of the story's location, the period is never specified, though various details suggest the story takes place sometime in the 1920s.

Throughout the story, Aiden experiences the same day eight times in eight different bodies—also referred to as hosts. On the first day, Aiden wakes up as Dr. Sebastian Bell and has no memory of who he is or how he arrived at Blackheath. All he remembers is a name—Anna—though he does not yet know who she is. Aiden discovers more information throughout the day and with each successive host.

Every day, a mysterious figure in a plague doctor’s outfit visits Aiden, relaying information about Blackheath and what Aiden must do to leave it. Over time, Aiden learns from the Plague Doctor that the eight-day loop has been happening for years, each previous time resulting in Aiden’s failure and the erasure of his memory.

To escape the time loop, he must solve the murder of Evelyn Hardcastle, a 29-year-old woman who spent the past nineteen years in France and whose family owns Blackheath. The murder—which, at first glance, appears to be a suicide—will happen that evening, at a a ball hosted by the Hardcastle family.

As Aiden investigates, he makes it his mission to not only discover the identity of the murderer but also to prevent the murder from happening in the first place. His investigation reveals several secrets about Blackheath and the people gathered there. He learns that, nineteen years earlier, Evelyn’s younger brother, Thomas, was murdered; the man suspected of killing him, Charlie Carver, was executed for the crime. He also learns Evelyn’s parents have arranged for her to marry the wealthy Lord Cecil Ravencourt, Aiden’s fourth host.

The Plague Doctor explains that two others are also trying to escape Blackheath—to free himself from this loop, Aiden must figure out the killer's identity before they do. One of the two is Anna, a young woman trapped in the loop as a maid at Blackheath. While Aiden switches hosts each new day, Anna’s host remains the same. Even though they are competing against each other, he feels connected to Anna and relies on her as a partner to help solve Evelyn’s murder—going so far as to promise to get them both out of Blackheath.

Matters are complicated, though, by Daniel Coleridge, the other person trying to escape Blackheath. Daniel uses deception and violence to get what he wants, going so far as employing a footman to stalk and murder several of Aiden’s hosts.

Eventually, Aiden and Anna defeat Daniel and the footman. By using what he learned from his various hosts, Aiden manages to save Evelyn’s life and reveal that her brother, Michael Hardcastle, was responsible for her attempted murder.

The Plague Doctor tells Aiden that he is now able to leave Blackheath. Aiden, however, refuses to leave without Anna. At this point, the Plague Doctor explains to Aiden that Blackheath is an elaborate prison; more than thirty years earlier, in the outside world, Anna had brutally murdered Aiden’s sister and was imprisoned in Blackheath for her crime. Aiden broke into the prison so he could punish...