They splice together human and animal DNA and create a whole new kind of being.
Director Vincenzo Natali calls "Splice" an "emotional horror film" but admits that there are some "pretty shocking things" in it.
"Both actors responded to the script, especially Sarah. I think she responded to it because it was so perverse," said Natali. "She, in fact, told me that when she was reading the script, she would read something and think, 'Are they going to go there?' And then we would."
"While it's sort of a Frankenstein story, unlike Frankenstein, it's not a father-son story where Dr. Frankenstein created, basically, a surrogate son. This is a mother-daughter story," Natali explained.
The "daughter" quickly develops into a creature of beauty. Then, things get really ugly.
"Making this film was very much like having a child. It was very much like a pregnancy, albeit a pregnancy that was 12-years-long and I feel like I'm finally giving birth, and I can't tell you what a relief that is," said the director.
"Splice" is rated R for disturbing elements including strong sexuality, nudity, sci-fi violence and language. It opens Friday.