With Waterloo, ABBA became an international act. But in the aftermath, they were almost written off as one-hit wonders.In Episode 2 of ABBA: Eras, Sara Cox tells the story of how the group pulled themselves back from the brink of obscurity - and found legions of new fans a very long way from Sweden.Featuring rare BBC archive material, expert interviews and lashings of ABBA’s indelible pop, this is your window into the musical genius and sheer perseverance that brought ABBA to their rightful place at the top.