But the album is personal to me and deals with the breakup of Celtic Frost. What did it mean to you early on — and now — to be supported by HR Giger? To have somebody established like that say, “Hey, ...

On the anniversary of its release, we look at how Celtic Frost's Monotheist gave the band the final album it deserved. Kirk and Robert from Metallica busted out Celtic Frost's The Usurper in Zurich.