Opium poppies may look like innocent flowers out of a painting by Henri Matisse, but deep within their pods lies a substance that can be processed into heroin, a highly addictive drug used by 13 million people worldwide. In wartorn Afghanistan, opium poppies can be grown easily and bring in much-needed cash. But growing poppies is just the start. Before poppy pods can hit the streets as “junk,” “horse” or “smack” (or as their chemical cousins, opium and morphine), they must undergo a long and complicated refining process.