The documentary explores the controversial use of marijuana and the evolution of mainstream society. From a dangerous narcotic, listed as a Schedule 1 Drug substance since the 1970s, to the rush to decriminalize it today. What has changed and why? What will the cannabis industry look like in five years? Will it retain its integrity as a homegrown industry or be co-opted by Big Business? Experts, growers, celebrities and politicians weigh in on the future of Cannabusiness.

In the heart of America's opioid epidemic, four men attempt to reinvent their lives and reenter society sober after years of drug abuse. Recovery Boys, from director Elaine McMillion Sheldon, is an intimate look at the strength, brotherhood, and courage that it takes to overcome addiction and lays bare the internal conflict of recovery and the external hurdles of an unforgiving society.

In recent years, close study of the aging process has opened up new ways that could help us all live healthier for longer. Can we move beyond treating individual diseases, and instead treat the aging process itself? But would a longer life necessarily be a better life? A loose-knit group of researchers believe the real breakthrough is extending our health span - the period of life spent free of disease". Hear from Laura Deming, who dropped out of M.I.T. at the age of 14 and committed herself to finding and funding projects that can expand the human health span, and Dr. Brian Kennedy, whose work in the basic biology of aging has been crucial to the development of countless other researchers' work.

Memory is the glue that binds our mental lives. Without it, we’d be prisoners of the present, unable to use the lessons of the past to change our future. From our first kiss to where we put our keys, memory represents who we are and how we learn and navigate the world. But how does it work? Neuroscientists using cutting-edge techniques are exploring the precise molecular mechanisms of memory". By studying a range of individuals ranging —from an 11-year-old whiz-kid who remembers every detail of his life to a woman who had memories implanted— scientists have uncovered a provocative idea. For much of human history, memory has been seen as a tape recorder that faithfully registers information and replays intact. But now, researchers are discovering that memory is far more malleable, always being written and rewritten, not just by us but by others. We are discovering the precise mechanisms that can explain and even control our memories. The question is— are we ready?

Horizon explores the strange and wonderful world of illusions – and reveals the tricks they play on our senses and why they fool us. We show how easy it is to trick your sense of taste by changing the colours of food and drink, explain how what you see can change what you hear, and see just how unreliable our sense of colour can be. But all this trickery has a serious purpose. It’s helping scientists to create a new understanding of how our senses work – not as individual senses, but connected together. It holds the intriguing possibility that one sense could be mapped into another.

In the fifth episode Neil deGrasse Tyson explores questions that have baffled scientists for centuries. Can we know the universe? Are our brains capable of comprehending the cosmos in all of its complexity and splendor?. We don't yet know the answers because our brain remains almost as much of a mystery to that questions as the universe itself. An abandoned orphan's dream opened the way to understanding the architecture of thought.