I think this movie gave away a lot too early on. The timing is really bad, like when the 'villain' first appears... it felt quite out of place. It wouldn't hurt to have some more development before. And the bathtub scene! Ridiculous. After that, I kept waiting for that thing when the whole movie was just the brilliant new idea the main character finally had for her new book. But of course that doesn't happen either!
This is a minimalist, smart, cleverly made cat-and-mouse thriller combined with tense & breathless horror. Although it is full of things we've seen all before in countless other movies, we can never get enough of them; when they're done very well! Isn't it so? The acting of Kate Siegel is great: her magnetic screen presence, her intense pale eyes and expressive face delivers authenticity & credibility all the way.
Come spesso capita in questo genere di film, un'idea assolutamente brillante non basta a realizzare un film veramente valido, ma in questo caso il risultato è decisamente sopra la media. I clichè sono molti, ma la tensione viene tenuta alta e diverse scene sono tutt'altro che scontate, cosa assai rara per questo filone cinematografico.