Chloe Sevigny felt foolish on the set of new thriller ZODIAC - because she found the book the movie is based on too boring to read. The actress attempted to read ZODIAC UNMASKED before shooting began but found it so "tedious" she gave up, only to find that all her castmates had studied the book about San Francisco's Zodiac Killer, and found it rivetting. She explains, "I started reading Zodiac Unmasked before we went into production and I couldn't get through it. I found it slightly tedious. "He (author Robert Graysmith) went so in depth into the details and I just wasn't that interested. I was frightened by the scarier bits and the details of the crimes. "I did, however, feel slightly embarrassed because all the men on the set knew so much about it and they had all these crazy details from the book."