Will Self continues his 50 kilometre circumnavigation of the Large Hadron Collider at CERN just outside Geneva - entirely on foot. Following the course of the Collider through the French and Swiss countryside, Will stops at regular intervals to descend to the tunnel below and view the experiments. So far Will has been feeling completely baffled. Following an ultimatum to his CERN hosts, he receives a crash course in particle physics from Professor Akram Khan of Brunel University. Producer: Laurence Grissell.