The Uncanny Inhumans #19
AN INHUMANS vs. X-MEN TIE-IN!
Maximus the Mad, exiled Inhuman Prince, has discovered the formula for Terrigen Crystals!
With his newly formed squad of Inhuman villains (including Triton?), he's traveling the globe gathering the necessary ingredients.
If he succeeds, he could end the war between Inhumans and X-Men in a single stroke - but where's the fun in that?