A hero is just someone who acts selflessly, out of concern for others, at personal risk and without the expectation of reward. In this episode, Michael Stevens asks employees to help him run a seemingly dangerous experiment, to see if they would blow the whistle to stop him.

Our relationship with destruction is not a simple one. It can release endorphins and relax our minds. It can amp us up and make us even more aggressive. It can even help us regulate our emotional reactions. Can violently breaking things calm us down? Or does it simply anger us more? Find out as Michael Stevens takes a look into our urge to destroy.

When it comes to illusions, optical illusions get all the attention. But the whole body you have can be fooled and can fool the brain. What is touch? Is it real, or is it just in our heads? Michael Stevens decides to find out.

We're going to see if forcing your facial expression can change the way you feel. If you remove the ability to make facial expressions with botox, will it affect how the people perceive emotions in them?
How do facial expressions affect emotion, and how does emotion affect facial expressions? Michael Stevens finds out when he explores the face.

To recruit actors for his rehearsals, Nathan opens an acting studio in Los Angeles, teaching 'the Fielder Method', which involves covertly observing and imitating unaware subjects. Feeling insecure about his own performance, Nathan reenacts the class with actors and a fake Nathan as the teacher while the real Nathan plays the role of Thomas, a student. Nathan makes his students immerse themselves in other people's lives while he immerses himself in Thomas's life, even living in Thomas's home.
Nathan returns to Oregon, where his 'son', Adam, is now a teenager. Nathan and Joshua, the actor playing Adam, decide that Adam should lash out due to resentment of his absentee father and develop a drug problem, a situation that mirrors Angela's own past. Adam suffers an overdose and is tended to by emergency responders played by Thomas and another Fielder Method graduate. After he runs away from home, the 15-year-old Adam reverts to a 6-year-old since Nathan plans to relive his son's earlier years.

Nathan stages a ninth birthday party for Adam, but faces a problem when Remy, one of the child actors who played Adam at age six, becomes attached to Nathan, calling him 'daddy' even after his scenes are over. Remy's mother explains that her son might have trouble understanding the difference between acting and reality. To discover what went wrong, Nathan repeats Remy's scenes with different actors including Liam (a nine-year-old Adam actor), an adult actor, and a mannequin. He then explores what might have happened if Angela had stayed with him and meets with the real Angela, who urges him to forgive himself, as her religious beliefs state.
In an attempt to truly understand the connection between parent and child, Nathan stages a new scenario in which he is Remy's mother Amber and Liam portrays Remy. They re-create the experience of appearing on The Rehearsal and becoming attached to 'pretend daddy' Nathan. After coming to the emotional realization that they should not have done the show, Nathan as Amber seemingly breaks character and tells the fake Remy, 'I'm your daddy.'