A look back at some of cinema's best-loved partnerships, from Fred and Ginger, Doris Day and Rock Hudson, to Newman and Redford, and even Nick Frost and Simon Pegg. With interviews and appearances on the BBC over the years, we tell the stories of the stars who, regardless of whether they were friends or rivals, audiences just loved to see up on the big screen together - their collaborations creating an alchemy that resulted in box office gold.