Best-selling young adult novelist Maggie Stiefvater, who wrote the very popular “Shiver” series about teen werewolves, was at the Cambridge Public Library on Thursday night to share her new novel, “The Raven Boys,” which tells the story of a young woman who’s told that if she kisses her true love, he will die. (Dramatic, right?) The book was just optioned for film by New Line Cinema and, according to The Hollywood Reporter, Akiva Goldsman of “A Beautiful Mind” has signed on to produce. Stiefvater told us by phone this week that she’s barely spent any time in Boston so she’s excited to get two gigs in the area (she has a second reading at 10 a.m. Friday at the Harvard Coop.) She also told us that despite the fact that her books are classified as young adult, about half of the people who show up to her readings are grown-ups. And in European countries such as Germany, she added, her novels are marketed like any other adult book. “There’s nary a teen to be found,” she said of her readings abroad.