"The Phantom Planet." Superman and Charlie Kweskill are transmuted to liquid in Aethyr's universe, then restored with Charlie in Superman's costume and with his old Kryptonian powers, and Superman in Quex-Ul's Kryptonian outfit.
Way back in 1961, Adventure Comics #283 introduced us to The Phantom Zone. Discovered by Jor-El, Superman’s father, the Phantom Zone was a sort of shadow realm where time seemed to stand still. Jor-El came up with the notion of sending criminals there, where they would live forever in a wraith-like existence. Once in the Phantom Zone, you didn’t age, and you couldn’t touch the outside world. You were left there with the others, condemned to think about your crimes until you were released.
Over time, Krypton’s worst criminals were sentenced to the Phantom Zone, including tyrants, mass murderers, and even world-destroyers. Ironically, their imprisonment in the Phantom Zone allowed these villains to be among the few to survive Krypton’s destruction. They devised a fearful plan during their imprisonment: one that would trap Superman himself in the Phantom Zone, and allow them to escape into the defenseless outer world…
