Welcome to Set explores how algorithmic technologies for emotion recognition and deception detection are made. With massive amounts of clips of actors and experiment participants, algorithmic lie detectors are trained with laboratory footage where the computer scientist becomes the director. Reenacting these film/data sets, I encounter sighs after the cuts, shaking legs out of frames, and laughters outside studios—how genuine emotions escape the emotion data sets. This film observes and questions the artificiality of artificial intelligence.