The Last Word by Taylor Adams

Emma Carpenter lives in isolation with her golden retriever Laika, house-sitting an old beachfront home on the rainy Washington coast. Her only human contact is her enigmatic old neighbor, Deek, and (via text) the house’s owner, Jules.

One day, she reads a poorly written—but gruesome—horror novel by the author H. G. Kane, and posts a one-star review that drags her into an online argument with none other than the author himself. Soon after, disturbing incidents start to occur at night. To Emma, this can’t just be a coincidence. It was strange enough for this author to bicker with her online about a lousy review; could he be stalking her, too?

As Emma digs into Kane’s life and work, she learns he has published sixteen other novels, all similarly sadistic tales of stalking and murder. But who is he? How did he find her? And what else is he capable of?