Corey Taylor had spent his entire night bellowing one blood-curdling scream after the other at a savage Vector Arena crowd who roared every word back at him.
But he saved his last shout of pain for his bandmates.
At the end of last night's Vector Arena show, a pummelling metal assault from the masked Iowa collective with little respite over two thrilling hours, Taylor finally revealed his true emotions.
Dressed like a freak from a Saw film, the 42-year-old ended Spit It Out - a grinding highlight from the band's first album - by slamming his microphone into the stage, clutching his left shoulder in agony, turning around and howling in relief at the eight men behind him.
He then ripped off a black neck brace he'd worn for the entire show and embraced Slipknot's silliest member Shawn "Clown" Crahan, the group's "percussionist" whose sole job during Spit It Out was to hit a keg with a metal baseball bat as hard as he could.
It was a moment of pure emotion that showed there's real pain behind those silly horror masks the group's nine members still insist on wearing, despite repeatedly proving over five albums of flexing metallic muscle they're no mere novelty act.
That's because Taylor recently had surgery for a debilitating neck injury, one he told the Herald could have left him paralysed.
Several months after the surgery, he still can't jump or headbang and isn't supposed to run. During past shows in New Zealand, including their last show here in 2008 at Trusts Arena, they're all things he did with physical abandon.
So yes, tonight's show, one of the band's last after a two-year tour behind their 2014 album .5: The Gray Chapter, may have lacked Taylor's usual manic enthusiasm, but his bandmates more than made up for it, from Clown's casual destruction of his rising drum kit during The Devil In I, to Sid Wilson's ridiculously entertaining dance moves in front of his turntables during The Heretic Anthem.
And Taylor did not let his injuries affect his voice. His wallpaper-stripping growl is still Slipknot's best weapon, and it was the highlight of a night of blistering intensity, from the wallowing grind of Psychosocial, to Left Behind's victorious chest-beating chorus and Duality's aching wail.
After delivering (sic)'s cathartic chorus near the end of the set, Taylor curled up in foetal position on top of a speaker, a glimpse of the pain he was going through and wouldn't fully reveal until after the show.
That chorus includes Taylor chanting, "You can't kill me" over and over again. It couldn't have felt more apt.
Where: Vector Arena, Auckland
When: Wednesday, September 26