“We’re like a threaded needle, never to be separated,” Wong Chia Chi (undercover as Mrs. Mai) sings to the man her resistance group has sent her to seduce with the end goal of his assassination. Their lovemaking is at times brutal, and Chia Chi is always filled with confusion and self-loathing for what she’s volunteered to do in hopes of overthrowing the Japanese occupation of Shanghai. Yet her feelings for Mr. Yee turn from faked passion to something a lot like love (albeit the depraved variety), and they boil to the surface at the most catastrophic moment. Director Ang Lee, who won an Oscar for Brokeback Mountain, clearly excels at depicting this type of conflicted, forbidden lust.