“This diary must never be published! This is my last will! And it must be obeyed!” August Strindberg wrote these words on the cover of a diary he kept from 1896 to 1908, the so-called Occult Diary, which chronicled not only his intellectual, spiritual, and artistic reorientation of the 1890s, but his passionate and all-consuming love affair and marriage to his third wife, the actress Harriet Bosse, 30 years his junior. Professor Gavel Adams spoke on Strindberg’s Occult Diary at the Swedish Collegium for Advanced Studies on 8 March 2016. She has been fellow at the Collegium during winter 2016. Her project there has been to finalize an English edition of the Occult Diary, and to write an introduction to it in English. The English edition will be published digitially in 2016 at Litteraturbanken, with a print edition planned to follow.