"Unusual Tales", a series presenting Steve Ditko's comics from 1957 to 1959 that are in the public domain.
Several quality Ditko bits in the art. It's always nice how he comes up with different alien city designs and space-ships for these stories. I especially liked the ships for the big final attack. You'll know what I mean when you see them.
Some links to check out:
Buy Ditko's creator-owned work
Find out about the fanzine DITKOMANIA
Check out new and upcoming Ditko publications
Download public domain comics, likely including the one this story is from
(scans in this series generally adapted to my personal tastes from those copies)
Click images to double up size.