Obvious quibbles with the title aside (at 'the top' of what, exactly?), this is the story of the girl group, from their formation on Popstars: The Rivals in 2002 to the release of their greatest hits album a decade later. Split into three chapters - The Definitive History, Solo Projects and Back Together Again - the documentary celebrates the band's biggest hits, explores solo projects such as Cheryl Cole's recent UK tour, Sarah Harding's film work and Nicola Roberts' passion for fashion, and catches up with all five a month before they go public with the announcement of their reunion. There also promises to be exclusive access to all the preparations that lead up to their launch and come-back, culminating in a headline performance at the Royal Variety Performance.