Elsa Keslassy International CorrespondentSF Studios and sales banner REinvent have unveiled the trailer for “The Pact,” Bille August’s psychological drama based on real events in the life of Karen Blixen, the Danish author best known for her autobiographical novel “Out of Africa.”The film depicts Blixen’s tumultuous relationship with Thorkild Bjørnvig, a promising young poet, after she returned from Africa.