Can we bridge the divide between "us" and "them"? At a time when the whole world seems to be polarizing into irreconcilable camps, Morgan Freeman sets out on a journey in search of the forces that push us apart, from intolerance of differences to fear of outsiders, and the possibilities of coming together.
Professor Marcus du Sautoy goes in search of answers to one of science's greatest mysteries: how do we know who we are? While the thoughts that make us feel as though we know ourselves are easy to experience, they are notoriously difficult to explain. So, in order to find out where they come from, Marcus subjects himself to a series of probing experiments.