Adventure Comics #300 GCG Graded 7.0 (1962)

*CGC Graded 7.0, straight cover with bottom lined up and not having Mon-El name cut off.*

Lana and Clark are accidentally transported to a strange world where Clark must make her think they both have superpowers in order to prevent her from guessing he's Superboy; At a regular meeting of the Legion of Super-Heroes, the Legionnaires lose control of their powers. Urthlo arrives and announces that he now controls the Legionnaires' powers and there is nothing they can do about it. But Saturn Girl comes up with a serum to temporarily cure Mon-El and immunize him against lead, and Superboy releases him from the Phantom Zone to knock out Urthlo, who turns out to be an automaton created by Lex Luthor sent into the future to destroy the Legion.; Vic asks Melissa to marry him so he can feel what it's like to lose a million dollars.; Pete loses his ice cream to Willie's dog.; Jerry takes Jane for dinner, but it's a cheap place.