Who says J.R.R. Tolkien's fantasy "The Lord of the Rings" isn't real? Certainly not Liv Tyler, who stars as the elf, Arwen UndÛmiel, who is in love with the human, Aragorn, played by Viggo Mortensen, in director Peter Jackson's screen adaptation. The film is the first in a trilogy based on the author's series. As PEOPLE reports, what drew Tyler, 24, to the film, "was this love story," the actress told reporters at a New York press junket recently. "When I read the (book's) appendix about (Arwen and Aragorn) for the first time I burst into tears. You don't see in the movie, but when Aragorn finally dies, she goes to where they met and lies down to die. I know that's very romantic but I really responded to it in a way that you would to "Romeo and Juliet" or some classic love story. That's something that lacks a lot in our world. I love the idea of these people who are so sure of their love that she's willing to risk so much for that." As for landing the plum role, "I was very overwhelmed," she said, "because I wasn't familiar with (the book) at all. I had visions of boys debating and talking about it in school, and I wasn't interested at all . . . although my mother was a very big fan of it."