Marvel Collectors' Item Classics #6

In "Iron Man Versus Kala, Queen of the Netherworld!", Iron Man finds himself pulled into the hidden realm of Kala, the enigmatic ruler of an underground kingdom who seeks to conquer the surface world. With his genius and suit's technology, Stark must convince the queen of the deadly cost of such a campaign—before her ambitions bring ruin to both her people and the world above.

In "Return to the Nightmare World!", Stephen Strange is called upon when a wave of sleepers can't be roused—leading him to the eerie Nightmare World, where the villain has begun abducting people during their dreams. With his mystical skills tested once more, Strange faces his old adversary in a battle that blurs the line between reality and the subconscious.

In "Beauty and the Beast!" from Marvel Collectors' Item Classics #6 (1966), the Hulk finds himself trapped beneath the earth, forced to serve the underground tyrant Tyrannus after the villain captures Betty. With the Jade Giant’s strength bound by the threat to her safety, only Rick’s courage may hold the key to breaking the spell—and unleashing the Hulk’s full fury.