This issue concludes the big battle with the Four-Armed Terror, unleashed on The Project by the Evil Factory. The Terror is a great villainous monster, which is probably why Kirby did a bunch of sketches with various characters (including the Hulk) battling him.
This story has a 15-minute countdown to the blow-up at the Project's atomic power plant as the Terror closes in, and Superman has to race through to stop it, while the Guardian and adult version of the Newsboy Legion are in pursuit. The funniest part of the issue is probably the scene with Morgan Edge, being told to flee the city by his Intergang contacts, not caring at all about anyone on his staff.
It's exciting stuff, but a bit off. Kirby originally had some other plans for this storyline, which apparently didn't match what DC had planned in their other books. Mark Evanier eventually used some of those plans as the basis for his LEGENDS OF THE DC UNIVERSE #14 story with Steve Rude a few years back.
Vince Colletta inks the 23-page story, with the Superman characters adjusted by Murphy Anderson. Neal Adams inks the cover, which features one of Kirby's collages, looking much better on cover stock than they usually did on newsprint (including the two-page spread with a collage in this issue).
This story is available in JIMMY OLSEN ADVENTURES BY JACK KIRBY v1.