I really liked this story. First, it features a villain I really like: Avalanche. Second, it features a second villain with the same powers—and we don’t see that very often. But it makes sense, doesn’t it? If a mutant gene could give one dude the power to make the Earth crumble, then why wouldn’t another get the same power?
Anyway, the second dude is Landslide (he’s one of the Outcasts), and he and Avalanche fight because Avalanche is breaking ground over a cave where Landslide lives with the mole people. Then Hulk shows up and pounds them both.
But perhaps best of all is the above “author’s note” on page one. A key element of the story is Betty Ross and Rick Jones surviving a plane crash, so Bill Mantlo adds a tongue-in-cheek reference to how often Chris Claremont loves to crash planes.