Cooking shows turned the humble garlic bulb into something that's essential to cuisines and into a multi-billion-dollar crop. Every year, humans consume nearly 50 billion pounds of garlic, and most of it comes from one country: China. But a lawsuit raises troubling questions about suppliers.

Today, worldwide, we each eat 27 pounds of chicken a year. Chicken's astonishing growth has been propelled and satisfied by a business that creates lives, and harvests them, at breathtaking speed and volume. But now the massive scale of production has exposed those in the chicken business to dangers large and small.
The ruthlessly efficient world of chicken production pits vulnerable growers against each other and leaves them open to vicious acts of sabotage.

Changing diets and dramatic price swings have put dairy farmers on the ropes and fueled a surge in lucrative but controversial raw milk sales. Proponents of raw milk have stated that there are benefits to its consumption, including better flavour, better nutrition, and the building of a healthy immune system. However, the medical community has warned of the dangers, which include a risk of infection, and has not found any clear benefit

Autistic minds provide windows into how we all think, feel, and behave. A complete brain science should be able to account for all kinds of minds and brains. As long as some minds remain a mystery, so too will all minds.
Michael Stevens travels to London to meet a blind, autistic savant with astonishing musical abilities, and volunteers to have his brain's function temporarily disrupted at UCLA's Neuromodulation Lab.

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.

The fourth episode sees host Neil deGrasse Tyson exploring our eternal quest to end hunger and honoring Nikolai Ivanovic Vavilov, pioneer of modern plant breeding, who risked his life for a discovery that would change the history of science. Vavilov's story is marked by both the tenacity and creativity and is particularly tragic. Interwoven into Vavilov's somber narrative are warnings and treatments of science and its ethical implications, especially when science itself comes under attack from political forces.