Don't fall for the blurb. It is misleading and sort of inaccurate. Here is a better synopsis for you.

Synopsis
A mysterious fog has enveloped the world, extinguishing all life on Earth except for a small island that shelters the world's greatest minds. They have managed to survive by creating a shield around the island.

Years after the fog, we meet Emory, a woman who is dissatisfied with her life on the island. Following her husband's death in an unexplained accident, she begins to doubt the ruling authority known as the Elders. She perceives the villagers' treatment as unfair and observes peculiar occurrences, such as people waking up with unexplained scratch marks on their bodies. Emory is the sole islander who questions the Elders, yet none of her fellow villagers share her skepticism.

Abi is an AI integrated with the consciousness of every islander, except for the Elders. She is built to be a voice of reason, to protect the humans from their tendencies to do evil.

One day, the lead scientist, a member of the Elders, is murdered. This act triggers a self-destruct sequence that Abi is unable to override unless the murderer is apprehended. Thrust into the role of detective, Emory's investigation uncovers startling truths about herself and the island.

Minor Spoilers Ahead
The story is told from a perspective of an Ai, connected to human consciousness via their mitochondrial DNA. The book is more scifi than a murder mystery, in my opinion. The pivotal murder takes place at 30% mark, leaving a short amount of pages for the mystery to unravel and culminate in a satisfying conclusion. Regrettably, each reveal unfruls to be increasingly underwhelming, failing to create a significant impact. This is largely attributable to poorly developed characters that never truly grow on you. Upon learning they are clones, not humans, the islanders’ lack of emotional response is striking, to say the least. Emory's investigation isn't about who did it but why they did it. And despite the murderer being in plain sight, she dedicates a substantial portion of the book to pursuing incorrect leads, neglecting the most obvious suspect.

A good mystery captivates with its character, engages with its plot, and grabs your heart with a reveal that neatly ties all threads together at the conclusion. This book, however, does not meet these criteria. Its plot fails to engage, its characters lack depth, and its reveals are both predictable and uninspiring.