This may seems like a quite a random interviewing combination - a comedian and one of the world's most celebrated scientists. However, unbeknownst to many, O'Briain himself also has a degree in theoretical physics, and it has actually been a lifelong dream of his to meet Hawking. In this documentary, the comedian spends time with his boyhood hero as he attends the world premiere of the movie made about his life, The Theory of Everything, and then at his home and place of work in Cambridge. In their frank chats, Hawking admits to how his condition can leave him feeling lonely at times, while Dara also meets Hawking's two children, Lucy and Tim, as well as his friends and colleagues.