In the first of a three-part series, Professor Dame Jocelyn Bell Burnell describes how she discovered pulsars, the by-products of supernova explosions which make all life in the universe possible. She describes the moments of despair and jubilation as the discovery unfolded and her excitement as pulsars took the scientific world by storm. Profoundly reflective about the nature of scientific discovery, she shares her thoughts on the connections between religion and science and describes how she see science as a search for understanding rather than a quest for truth.

In the second of a three-part series uncovering the minds behind some of the greatest scientific discoveries of our age, James Lovelock explains how his maverick way of thinking led him not only to technical breakthroughs in atmospheric detection systems on Earth and Mars, but also to Gaia - a new way of thinking about the Earth as a holistic, self-regulating system. He tells of his struggle against the scientific consensus of the day, the ridicule of his peers and his passionate belief that the mainstream scientific establishment stifles intellectual creativity.

The final part of this series looking at three brilliant contemporary scientists features Sir Tim Hunt, awarded the Nobel Prize for his discovery of the mechanism of how cells divide - a discovery fundamental to the life and growth of every single creature on the planet, as well as a vital clue into the mystery of cancer. Hunt recalls moments in his life that provided inspiration for his career as a scientist, from his father's intent scholarship which shaped his early methods to his mother's battle with cancer and the influence of this on his current position at Cancer Research UK. In his own words, Hunt recounts the events that informed his discovery, from chance encounters to life-changing conversations and reveals his own opinions on the thought processes, both logical and emotional, that led to his extraordinary discovery.

For palaeontologist Professor Jenny Clack, who solved one of the greatest mysteries in the history of life on Earth, success was far from inevitable. She recounts how she had to overcome a series of setbacks before she found and described the fossil Acanthostega, a 365 million-year-old creature that offered dramatic new evidence of how fish made the transition onto land.

Andre Geim reveals how his playful approach to research helped him uncover the properties of graphene, the world's thinnest material, and won him a Nobel Prize.

Professor Richard Dawkins reveals how he came to write his explosive first book The Selfish Gene, a work that was to divide the scientific community and make him the most influential evolutionary biologist of his generation. He also explores how this set him on the path to becoming an outspoken spokesman for atheism.