« The mother of all lies » follows the director as she goes to her parent’s house in Casablanca to help them move. In the family home, as she sorts out her childhood effects, she discovers a picture of children sitting in a yard. At the back, a little girl is sitting on a bench smiling shyly at the camera. It's the only picture she has of her childhood, the only souvenir her mother can give her. But Asmae is convinced that she is not that little girl in the photo. In the hope of getting her parents to open up, she manipulates this small incident to bring back other memories she suspects. The photo becomes the starting point of investigation in which she questions every small lie her family has told her. Gradually the memories of the entire neighborhood are explored.