Korn star Brian 'head' Welch was hesitant to rejoin the group because he didn't want his bandmates' bad habits to lead him astray and back onto alcohol and drugs.
The guitarist quit the band in 2005, and ended up finding God and kicking his addictions to booze and methamphetamines.
He reteamed with his old friends earlier this year (13), but before he agreed to the reunion, he wanted to make sure they were clean and sober.
And he admits that watching frontman Jonathan Davis perform onstage gave him cause for concern.
Welch tells Revolver, "I saw him and he wasn't doing good. It made me reluctant to come back at first because I didn't know if he was on drugs or what. I really don't want to be around that again. I felt in my heart that I was supposed to be back in the band, but I was still worried about Jon."
And Davis admits his old friend's concern was justified - he was in the process of kicking prescription anxiety medication Xanax.
He explains, "I wasn't doing it to get high or anything. I just wanted to feel sane. But then I had a check-up and my doctor said, 'We've got to get you off this'."
The Korn singer checked into a Bakersfield, California treatment facility for 10 days in a bid to kick his habit under supervision.
He adds, "They put me on phenobarbital and all this s**t to keep me from going into seizures and watched me around the clock. That s**t's evil. It's harder to kick than heroin."
Knowing that David was going to be Ok and clean, Welch then turned his attention to fellow guitarist James 'Munky' Shaffer - because he wanted to make sure he was no longer knocking back alcohol like he used to before Head quit the band.
He adds, "I couldn't have been around the drunk Munk. He's too angry. Whenever I'd hear him outside the buses roaring like a wild animal, I'd make sure I stayed away from him."
Head's fears were allayed and he hit the stage with Korn for their Carolina Rebellion concert in May (13). He has now become a permanent member again.