When Hollywood writes books, the books are almost never worthwhile. (Dear Ethan Hawke: You're a wealthy, pretty, vacant man, not a beat novelist.) But John Sayles's films (Lone Star, Silver City) are so writerly that his new novel from McSweeney's, A Moment in the Sun, demands serious attention. And as attention grabbers go, it's a doozy: At nearly a thousand pages and featuring a cast of hundreds, Sun is an unapologetically liberal novel set at the turn of the 20th century about unjust war, racism, and Mark Twain. (Elliott Bay Book Company, 1521 10th Ave, 624-6600, 7 pm, free)