18 year-old Marco, in the summer of high-school final exams, unexpectedly ends up on a road trip to San Francisco with Mary, a classmate of his, nicknamed ‘the nun’. Mary’s company is, to Marco, a real catastrophe. When in California, the two of them will be guests of Matt and Paul, a young gay couple: the four will have to face problems and prejudices and will live an experience that will forever change their lives.