sophie is a girl approaching her 15th birthday. She encounters first some odd philosophical questions and then the first chapter of a written philosophy course in her mailbox. Sophie starts to learn about the historical beginnings of philosophy. At the same time, Sophie is curious who is giving her this course. Sophie also begins to receive postcards addressed to Hilde, a girl also approaching her 15th birthday, from Hilde's father Albert Knag, a Norwegian Major in the UN Force in Lebanon.