The Ice Beneath Her by Camilla Grebe

The Ice Beneath Her by Camilla Grebe is a great pick for fans of "Nordic Noir" or thrillers in general. It starts with police investigating a gruesome beheading that reminds them of a similar case from 10 years ago. They don't know who the dead woman is, only that she is found in the house of a high-profile CEO, Jesper Orre, and that he himself is missing as well. Then we rewind two months and meet a young woman named Emma, who works in one of Jesper's clothing stores and is having a secret affair with him. As the police work on unraveling the case and finding the killer in real time, we watch Emma and Jesper's relationship unravel in the past.

At first this seems like a slow plod to an inevitable conclusion (it's always the boyfriend, right?), particularly when you throw in the third voice of Hanne, a consultant brought in on the case who assisted with the previous investigation a decade ago. Her storyline slows down the pace a bit; she's been diagnosed with early-onset dementia, is having martial difficulties, and can't quite trust her memory, or lack of, anymore. This serves as a metaphor for the entire book though, as the other characters' memories cannot be trusted either. All to say that there's definitely an unreliable narrator, and while the "twist" becomes somewhat evident about halfway through, it's still an interesting one and worth reading to its conclusion. You might not say "I never saw that coming..." but it is clever and will leave you feeling thoroughly creeped out.