Be careful of strangers and hurry home, says a mother to her daughter, knowing that the world is a frightful place but not wishing to swaddle a child in fear. Girls grow up scarred by caution and enter adulthood eager to shake free of their parents’ worst nightmares. They still know to be wary of strangers. What they don’t know is whether they have more to fear from their friends. Most women who get raped are raped by people they already know — like the boy in biology class, or the guy in the office down the hall, or their friend’s brother. The familiarity is enough to make them let down their guard, sometimes even enough to make them wonder afterward whether they were “really raped.” What people think of as “real rape” — the assault by a monstrous stranger lurking in the shadows — accounts for only 1 out of 5 attacks. So the phrase “acquaintance rape” was coined to describe the rest, all the cases of forced sex between people who already knew each other, however casually. But that was too clinical for headline writers, and so the popular term is the narrower “date rape,” which suggests an ugly ending to a raucous night on the town. These are not idle distinctions. Behind the search for labels is the central mythology about rape: that rapists are always strangers, and victims are women who ask for it. The mythology is hard to dispel because the crime is so rarely exposed. The experts guess — that’s all they can do under the circumstances — that while 1 in 4 women will be raped in her lifetime, less than 10% will report the assault, and less than 5% of the rapists will go to jail. When a story of the crime lodges in the headlines, the myths have a way of cluttering the search for the truth. The tale of Good Friday in Palm Beach landed in the news because it involved a Kennedy, but it may end up as a watershed case, because all the mysteries and passions surrounding date rape are here to be dissected. William Kennedy Smith met a woman at a bar, invited her back home late at night and apparently had sex with her on the lawn. She says it was rape, and the police believed her story enough to charge him with the crime. Perhaps it was the bruises on her leg; or the instincts of the investigators who found her, panicked and shaking, curled up in the fetal position on a couch; or the lie-detector tests she passed. On the other side, Smith has adamantly protested that he is a man falsely accused. His friends and family testify to his gentle nature and moral fiber and insist that he could not possibly have committed such a crime. Maybe the truth will come out in court — but regardless of its finale, the case has shoved the debate over date rape into the minds of average men and women. Plant the topic in a conversation, and chances are it will ripen into a bitter argument or a jittery sequence of pale jokes.