In this tightly wound, enthralling story reminiscent of Agatha Christie’s works, Lo Blacklock, a journalist who writes for a travel magazine, has just been given the assignment of a lifetime: a week on a luxury cruise with only a handful of cabins. The sky is clear, the waters calm, and the veneered, select guests jovial as the exclusive cruise ship, the Aurora, begins her voyage in the picturesque North Sea. At first, Lo’s stay is nothing but pleasant: the cabins are plush, the dinner parties are sparkling, and the guests are elegant.