The young Mr. Mxyzptlk had been introduced into the Superboy’s world in his own book, and makes his first appearance in the Superboy series in Adventure in issue 306 (March 1963).
Bored of school in the 5th Dimension, he heads to Smallville where he tricks Lana Lang, and then Superboy, into heading to his dimension while he runs wild in their hometown.
It’s a fun little tale, which gives the reader more of a view of the 5th Dimension world than is generally seen.
At a time when most comics had a supporting cast that could be counted on one hand, the Legion of Super-Heroes just kept adding more and more characters into the mix. This story introduced not only five new heroes, but even banded them into a supporting team, with the unenviable name of the Legion of Substitute Heroes.
Polar Boy, Night Girl, Stone Boy, Fire Lad and Chlorophyll Kid are all rejected for Legion membership. They do get nifty flight belts as parting gifts, though.
Undeterred, they form their own team, and hang out in a cave just outside the city.
We learn a little of the origin of each hero. Polar Boy is from a very hot world where everyone has the power to radiate cold, and Stone Boy is from a world where people “hibernate” by turning to stone. Night Girl lives on a world shrouded in darkness, so was unaware that her powers faded in sunlight until she came to apply for Legion membership. Fire Lad acquired flame breath after exposure to a meteor. But the best of these is the origin of Chlorophyll Kid, whose ability to stimulate plant growth came after falling into an experimental solution as a child.
The Legion really take a back seat to the Subs in this story. After a few attempts to help the Legion, the Subs discover that some unmanned rockets the team is fighting are really transporting alien plant life as part of an invasion. They head to the world the ships are coming from, and destroy the floral army.
The people of Earth, and the Legion of Super-Heroes, are unaware of the achievement of the Subs, but this team of rejects has proved themselves to the readers, and they would remain frequent supporting characters through the Legion’s run in Adventure.
This is also the first of Edmond Hamilton’s stories in this run. While Jerry Siegel’s Legion tales tended to be very much a part of the Superman universe, Hamilton was more interested in expanding the Legion’s own reality, and is my favourite of the Legion’s scripters during this early period.