This weekend it all ends – Black Sabbath and Ozzy Osbourne will take their final bow, onstage in front of near 50,000 fans in their hometown of Aston, supported by some of the best bands on the planet. Looking ahead to arguably the greatest metal gig of all time, Tony Iommi, Geezer Butler and Sharon Osbourne take us through the show itself, the heady mix of joy and trepidation, and why this is the perfect send-off for the godfathers of heavy...