Sir Nicholas Hytner interviews living legend and playwright Alan Bennett on the eve of his 80th birthday. Ranging across 40 years of his work for stage, television and cinema, it is the first time these long term collaborators (The Madness of King George, The History Boys and more) have engaged in a full-length debate on television about the art of what they do. Includes clips of eight of Bennett's productions from Forty Years On (1968) to The Habit of Art (2009).