https://www.thepennedsleuth.com/blog/the-woman-in-cabin-10-by-ruth-ware-book-review

The Woman in Cabin 10 is a mystery/thriller story of a travel writer’s nightmarish cruise. Lo Blacklock witnesses a murder, someone is thrown overboard in the night. However, all passengers are accounted for, leaving Lo to wonder if she is going mad or if there is a plot against her after what she witnessed.