ACTION COMICS (1938) #377

Cover by Curt Swan, inks Neal Adams Superman has escaped the ring of Green Kryptonite dust circling Earth, but can he survive… The Cage of Doom ? Story by Otto Binder, art by Curt Swan/Jack Abel Superboy has once again travelled to the 30th Century to meet with his friends the Legion of Super-Heroes, but can even their combined powers stop Urthlo? Story by Jerry Siegel, art by John Forte/Al Plastino (Plastino page 4 & Superboy/Luthor heads) letters by Milton Snappin