Abba's Bjorn and Benny talk about their 'magical' upcoming shows

Benny and Bjorn from Swedish supergroup Abba talk about the band's upcoming shows which kick off on Friday at their own arena in east London. Avatars of the group sing and dance on stage while a live band plays, Benny describes this as "magical" and "witchcraft" while Bjorn says "it's a strange and wonderful thing".