Mary's apartment explodes, completely consuming her in mysterious circumstances, and the incident was certainly planned. Who would kill a young and innocent engineer who had never been involved in anything before? She left her only friend, Leila, a bag with an unremarkable white card on it, with a few numbers, a yellow duck, and a piece of paper with a person's name written on it. Her friend finds herself facing a highly complex puzzle and is forced to put the pieces together, one next to the other, to answer the puzzling question: Who killed Mary Al-Hawi? But you won't see the complete picture until you place the last piece.