It’s a damn busy night for Milwaukee: Not only do we get an appearance from a Beatle (it’s Ringo, but still) but also one from the infamous author Salman Rushdie, who reads from his newest book, The Enchantress Of Florence, a meticulously researched tome set in the Mughal Empire, tonight at 7 p.m. at the Schwartz Bookshop in Shorewood. Rushdie’s breathless prose is exciting in its own right, but it risks being overshadowed by that ever-so-slight chance that one of Ayatolla Ruhollah Khomeini’s assassins may emerge and try to off the controversial novelist. Here’s hoping Schwartz Bookshop has strong security.