Being an interesting story in general, the book still runs the risk of loosing the reader's attention. There's a lack of generous descriptions and first hand perspective. Kate's feelings isn't always clear. She often seems unaware, or even ignorant, of the danger she is in - which only serves as a diminishing factor of the thrilling element. When the reader gets to enter her mind, it's during the constant Shakespeare reasoning that mark the novel. The characters are overshadowed by academic speculations, and the book gives the impression of a report of arguing and reasoning about a missing play and Shakespeare's true identity, rather than a thrilling, fictional story with characters. The fact that it resembles a thesis about the aristocracy of the 1500's is fascinating at first, but becomes somewhat tiresome, and might entertain already well-read researches and professors rather than a common reader interested in history and literature.
The element that destroys the novel is also what saves it, in a way - Carrell's genuine interest in Shakespeare and the extensive research, serving as the base of the novel, naturally mixed with her own theories and fiction. The material could have made a great story, if not being too dominant and excluding. Even though it's taken too far, it's interesting to enter a world swarming with well-read academics able to quote every line of Shakespeare.