Immortals and Inhumans
Nowhere on the cover does it mention the highlight of this issue. True, the story about a de-powered Thor's battle with Loki is better than his recent entanglement with the Circus of Crime. Also true that the art here is a bit better than some of the other recent issues - Kirby is really coming into his own three decades after his start in the medium!
But the highlight of this better-than-average issue is the backup story, 'The Reason Why!', which reveals the origin of The Inhumans. Co-credited to Stan Lee and Kirby, this is the kind of creative storytelling that made Marvel the king of the comics world in the 1960s.