Angus Young has revealed that AC/DC members knew his brother was losing his grip on reality during the band's Black Ice tour. He says sheer determination kept Malcolm going during the 2008-2010 period. Brian Johnson said there were dates on the tour '...he'd be Malcolm again. And, at other times, his mind was going', making it difficult for band members to gage how aware he was of what was going on around him. Johnson credits Malcolm for making it through, calling Malcolm 'brilliant' for managing to take the stage every night, including those times he seemed out of it. The front man said, 'God knows what went through his mind in some nights when he wasn't that well.'