lAs she more than confirmed with her best-selling 1996 novel, "I Was Amelia Earhart," [JANE MENDELSOHN] knows a good myth when she sees one. Combining a savvy intelligence with lyrical prose, she recognized in the Earhart legend all the fertile ground that lies between fable and history _ all the hopes and dreams and dark what- ifs, enhanced by her own free-for-all imagination. This shrewdness of judgment is not all that common in literary fiction, where a certain loftiness of vision can preclude steelier insights about democratic tastes. Mendelsohn has an appreciation for both: She may love a finely wrought sentence for its own sake, but she also understands why America might fall for the bedtime story behind it. She grasps the allure of "Carrie" as well as "Sister Carrie," in other words, as "Innocence" testifies. It's a minor but sophisticated little piece of Gothic Pop - sinister, campy, as sure of its intentions as Norman Bates. Borrowing classic ingredients from the genres of horror films and popular literature, Mendelsohn has concocted a coming-of-age tale about a Manhattan girl's adolescence; this is a story of innocence, all right, but that nebulous concept today means finding your way in a media-saturated, sometimes dangerous culture. If Beckett Hirsch, our desperate, likable protagonist, seems frozen somewhere between "Revenge of the Vampire Sluts" and "Catcher in the Rye," that's because the world she's grown up in is beholden to both.