This is a chilling and suspenseful thrill-ride for readers! At first, readers will suspect one of the characters in the novel as being the problem, but as the novel goes on, readers can see what is really happening. All the while, the main character, Margot, an orphan teen who has come to live in a sprawling historical mansion and to serve as a companion for a teen who is mute and "sick" with some sort of unspecified illness. The writing is fast-paced and sharp, and readers will be unsure of the ending until the final pages are turned. Unsettling, dark, and entertaining! I would highly recommend this book to fans of mystery, suspense, and horror books. It is written for YA and the characters are in their teens, but adults will enjoy it just the same. There is a very tiny bit of a romantic element to it, but the overall genre is definitely thriller. Loved it! Thank you to Bookish First for the copy of this book.