Emma Caulfield's feature-film debut, Darkness Falls, has grabbed the US number one movie slot in its opening weekend.

In the film Caulfield, better known as Anya, plays the sister of a young boy who is being hunted by a malicious spirit known as "The Tooth Fairy."

Speaking to Sci-Fi Wire, Caufield says she took the role solely for the chance to work with director Jonathan Liebesman. "I had seen a short film that he had done, and even though there wasn't any script or anything at the time, I said, 'Wow, I'd go get the guy coffee.' I really wanted to work with him."

Despite the horrific elements, Caulfield said she would classify the film as more of a psychological thriller. "I didn't see it as a horror film," she said. "I mean... not like a slasher horror film. It's definitely not a Friday the 13th or anything like that. You hear a lot. You think you see a lot, but you don't really see a lot, because it's so quickly cut and it's so dark."