"The Super-Planet of Clark Kent and Lana Lang!": 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.
Adventure Comics #300 is an issue of the series Adventure Comics (Volume 1) with a cover date of September, 1962.
Appearing in "The Super-Planet of Clark Kent and Lana Lang!"
- Alien Beasts (Single appearance)
- Unknown Planet
Synopsis for "The Super-Planet of Clark Kent and Lana Lang!"
Appearing in "The Face Behind the Lead Mask!"
- Legionnaires as statues on splash panel
Synopsis for "The Face Behind the Lead Mask!"
When the powers of the Legionnaires go out of control, they summon Superboy to the 30th Century to aid them. They discover the cause is a lead masked villain called Urthlo. When Urthlo drives back Superboy with Green Kryptonite vision, Superboy frees Mon-El from the Phantom Zone long enough for him to defeat Urthlo, who turns out to be a robot sent to the future by the teen-age Lex Luthor. But when the lead antidote (Serum XY-4) created for Mon-El proves to only be temporary, he is returned to the Phantom Zone to save his life. (12 pages)
- Includes a 1/2 page Varsity Vic, a 1/2 page Little Pete and a 1 page Jerry the Jitterbug gag features
- Begins Legion of Super-Heroes series which runs until Adventure Comics #380.
- First appearance of the Science Police
- In this issue, the Legion of Super-Heroes is said to exist in the 21st Century. Later, it will be changed to the 30th Century when reprinted in Action Comics #377.
- "The Face Behind the Lead Mask" is reprinted in Action Comics #377, Adventure Comics #497, Legion of Super-Heroes Archives Vol. 1, Showcase Presents: Legion of Super-Heroes Vol. 1 and Superman: Tales from the Phantom Zone.
- John Forte did the main art of the Legion feature with Al Plastino adding the faces for Superboy.