Killing Kennedy begins in 1959, at major turning points for both the future president and his assassin. John F. Kennedy (played by Rob Lowe) is in Washington, D.C., preparing to announce his presidential candidacy, while Lee Harvey Oswald finds himself in the U.S. embassy in Moscow, renouncing his U.S. citizenship. These two events start both men-one a member of one of the United States' most wealthy and powerful families, the other a disillusioned former Marine and Marxist-on a cataclysmic track that would alter the course of history". Throughout the film, we see their highs and lows, culminating in not one but two shocking deaths that stunned the nation. Based on the best-selling book by Bill O'Reilly and Martin Dugard.

We move around in space, but we are stuck in a prison of time moving ever forwards. Einstein said, 'The distinction between past, present and future is only a stubbornly persistent illusion.' Is our experience of the ticking clock merely a trick of the mind? Could science ever make the clock move backwards? Experiments in quantum physics are showing that the future influences the present: what happens later limits the choices we think we have now. The laws of physics say visiting or talking to ourselves in the past is possible – but changing history once we get there is not.

In the last in the series Professor Jim Al-Khalili explores how studying the atom forced us to rethink the nature of reality itself. He discovers that there might be parallel universes in which different versions of us exist, finds out that empty space isn't empty at all, and investigates the differences in our perception of the world in the universe and the reality.

We live our lives pursuing happiness 'out there' as if it is a commodity. We have become slaves to our own desires and craving. Happiness isn't something that can be pursued or purchased like a cheap suit. This is Maya, illusion, the endless play of form. In the Buddhist tradition, Samsara, or the endless cycle of suffering is perpetuated by the craving of pleasure and aversion to pain. Freud referred to this as the "pleasure principle." Everything we do is an attempt to create pleasure, to gain something that we want, or to push away something that is undesirable that we don't want. Even a simple organism like the paramecium does this. It is called response to stimulus. Unlike a paramecium, humans have more choice. We are free to think, and that is the heart of the problem. It is the thinking about what we want that has gotten out of control. The dilemma of modern society is that we seek to understand the world, not in terms of archaic inner consciousness, but by quantifying and qualifying what we perceive to be the external world by using scientific means and thought. Thinking has only led to more thinking and more questions. We seek to know the innermost forces which create the world and guide its course. But we conceive of this essence as outside of ourselves, not as a living thing, intrinsic to our own nature. It was the famous psychiatrist Carl Jung who said, "one who looks outside dreams, one who looks inside awakes." It is not wrong to desire to be awake, to be happy. What is wrong is to look for happiness outside when it can only be found inside.

Particle physicist Prof. Brian Cox asks, 'What time is it?' It's a simple question and it sounds like it has a simple answer. But do we really know what it is that we're asking? Brian visits the ancient Mayan pyramids in Mexico where the Maya built temples to time. He finds out that a day is never 24 hours and meets Earth's very own Director of Time. He journeys to the beginning of time, and goes beyond within the realms of string theory, and explores the very limit of time. He discovers that we not only travel through time at the speed of light, but the experience we feel as the passing of time could be an illusion.

Are the rings of Saturn a real celestial phenomenon or merely a cosmic Illusion? Technology allows the experts to get closer to the furthest planet visible to the naked eye. Old questions are answered and new ones arise. Does Saturn hold the key to Earth's weather and will one of its moons supply us with all the oil we'll ever need?