To survive Mars, our species will need to evolve how we eat, drink, and build our homes. Will we need our genes to evolve as well? Sometime in the future humans will leave Earth to colonize Mars, and in doing so will begin to adapt to life on another planet in surprising ways. Evolutionary biologist Dr. Scott Solomon foresees a series of changes to our species from the size of our hearts and heads to the pigments in our skin.

In the fourth episode, several women recall their harrowing experiences with one man's heinous attempts at virtual blackmail, aimed at obtaining sensitive sexual material.
A woman tells us: 'I received a message from a man who said: Send me a naked picture or I will kill you'. This young woman was able to add her case to those of other women who were encouraged to denounce and expose the harasser. No one is completely invisible on the Internet.

Frontline and service workers have borne the health consequences of the pandemic, increasing racial and economic disparities. Certain robotic and AI applications are accelerating as the value of human workers is further questioned. Determining the likely areas of job growth and training needs is difficult. Post-secondary education has become more virtual and its costs, more controversial. How can we predict job growth, training needs and the role of education in order to prepare for the work of the future?

We learn as much from victory as we do from loss. We employ strategies to gain the advantage, unconventional methods to overwhelm adversaries. One dedicated force steeped in mystique has always been part of war. Special operations, elite and unseen. Their presence felt by lethal attack. From the biblical era to the future of warfare, the battle environment is reshaped and redefined by special operations. Special Operations soldiers have come out of the trenches and are entering new domains of warfare.

A look into how the body defends itself against all odds through the stories of a nature survivalist, rancher twins, a doctor who survived Ebola and a cancer therapy recipient. The Immune System, essential to our survival every second, is the most complex and least understood piece of our biology.

After losing his drive to continue surfing at Nazaré, Garrett McNamara decides to return to competitive surfing at other big-wave sites. In order to compete in a tournament at California's Mavericks surf site, he must surf there regularly, something that he has done many times in the past. McNamara returns to Mavericks only to suffer a horrific injury on a wave he should have aced.