Kirby had never read a Green Arrow story and, when he took a look at them, thought they were unremarkable. So he began to introduce a more overt science fiction feel into the tales. This didn't last long--Kirby soon left DC after a dispute with Schiff and the G.A. stories reverted to a less fantastic tone. But, gee whiz, it was fun while it lasted.
Kirby drew a total of 11 stories, while also writing, re-writing or co-plotting them in his effort to send them off in a more imaginative direction. What he accomplished isn't his best stuff--he needed characters like the Fantastic Four, Thor, the New Gods and Kamandi to really allow his imagination to soar. But he still told some clever and entertaining stories.
That brings us to Part 2: "Prisoners in Dimension Zero." Trapped in a dimension populated by giants, Ollie and Roy discover the mystery arrows were being fired by some snotty kid with a toy bow. Not long after that, they discover that this dimension also has a Robin Hood-esque hero--called Xeen Arrow. The tiny heroes manage to help Xeen Arrow foil a robbery. Deducing that a comet that recently passed by opened the rift between dimensions, Xeen Arrow straps G.A. and Speedy to a Xeen-sized arrow and fires them back through the rift just before it closes.
The story totals only 12 pages, so it necessarily moves along briskly without giving us much in the way of characterization. (In fact, for the first few decades of his existence, Green Arrow really didn't have a distinct personality. It was Denny O'Neil and Neal Adams who eventually turned him into a street-wise crusader.)
But the basic plot and Kirby's visuals make this a lively and enjoyable tale. I especially like his Zero Dimension giants; they're pretty much just giant humans, but slightly odd facial designs and a subtle distortion of bodily proportions give them an appropriate alien-esque aura. And when all else is said and done, riding a giant arrow through a dimensional rift is simply awesome.