Dr Alithea Binnie (Tilda Swinton) is an academic - content with life and a creature of reason. While in Istanbul attending a conference, she happens to encounter a Djinn (Idris Elba) who offers her three wishes in exchange for his freedom. 

This presents two problems. First, she doubts that he is real and second, because she is a scholar of story and mythology, she knows all the cautionary tales of wishes gone wrong. The Djinn pleads his case by telling her fantastical stories of his past. Eventually she is beguiled and makes a wish that surprises them both.