This book is about four women who were high school best friends and endured a traumatic event during boarding school. Something happens that brings them all back to the town they went to school in, and a little Agatha Christie-style mystery ensues. I really enjoyed it and read it in two days. I will say that I liked The Woman in Cabin 10 a little better, but this is definitely still a great followup. Ruth Ware is definitely becoming one of my favorite authors in the thriller/mystery space!