What's behind a pulse? The second episode dives into the world of an ice climber, a bus driver, a woman in labor, and a senior dance club to show how the human heart and the circulatory system power our physical and emotional lives, and create the pulsing rhythm of our world.

The nervous system is fundamentally electric. When we move our arm, it moves because a electric signal has been sent to the muscle that controls it. Now, because the brain is electric, we could also use electricity to record what the brain is doing or bypass it entirely, and control a body. That means that we could restore movement to people who are paralyzed, feel through an artificial hand as if it was our own, and even read people's minds.
Michael Stevens explores how electricity can be used to move cockroaches, control other peoples' limbs and even read peoples' thoughts.

Magic mushrooms, long considered sacred by the Indigenous Mazatec in Mexico, become the subject of scientific studies measuring the intense effects of its Psilocybin and its potential therapeutic use.
In the second episode, we are introduced to Ben, who’s battled with crippling Obsessive-Compulsive Disorder (OCD) his entire life. When he had his firstborn, Ben’s life became full of panic attacks regarding his son’s safety, and he knew something had to change. Ben signed up for a psilocybin-assisted therapy clinical trial which was testing whether the psychedelic could help people with severe OCD. In the session under the influence of psilocybin, Ben felt decomposed and eventually grew into a tree. While living as a tree, he saw his human self, playing with his child. Though this sounds scary, from Ben’s perspective, it was beautiful. He was one with the universe, seeing himself in the ultimate third-person perspective. Finally, he saw how it could be different if he didn’t let his OCD control him. And several months out, all the symptoms disappeared.
Ben’s story is one of many told in this series, which gives hope that help is right around the corner for the millions who suffer —often in silence— with debilitating mental disorders. But Michael Pollan’s work is showcasing the success stories. Often, even in the most successful trials, psychedelic-assisted therapy only helps up to a third of people enter remission. More frequently, patients are helped —sometimes substantially— but they still suffer with their illnesses and some people aren’t helped at all.

Chris turns to longevity doctor Peter Attia to find out how changing his eating habits can help his quest for longevity. Ironically, the answer is to eat no food at all for four long days. If he can bear the hunger, fasting will unlock his body’s own anti-aging powers and give Chris the edge he needs when he tries to hunt for his next meal … by spearfishing off the Great Barrier Reef.

Follow three women at risk of developing Alzheimer’s and join a groundbreaking study to try to prevent the disease, while sharing their ups and downs, anxiously watching for symptoms, and hoping they can make a difference. Barb, Sigrid, and Karen all had mothers with Alzheimer’s and witnessed first hand the devastation wrought by the disease, not only on the mind and body, but on patients’ families.

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.