Board Thread:Speculation House/@comment-14909251-20170522044827/@comment-4010415-20170830004215

Arkantos95 wrote: Adam said it was time he returned to Mistral back in V3 during the flashback, but that's about it. Indeed, which also helps point to the possibility that the White Fang HQ is somewhere in the Kingdom of Mistral.

(It also explains where Adam was throughout Volumes 1 and 2. He went to Mistral.)