The Young Justice season 3 finale teased the appearance of the Legion of Superheroes in season 4. There is some irony that the first superhero team made entirely of teenagers in comic book history should be based in the far future and it is also fitting that they should be brought into an animated series that is devoted to profiling the young heroes of the DC Comics universe.
Young Justice: Outsiders episode 26, "Nevermore", ended with a private party at Bibbo's Diner in Metropolis. The founding members of The Team and their loved ones were waited upon by a blonde woman, whose hair was pulled back in a pony tail and whose face remained hidden. The final shot of the episode was a close-up on the woman's hand as she refilled Miss Martian's coffee mug, revealing her to be wearing one of the signature flight rings of the Legion of Superheroes.
Nothing has been said yet regarding the story of Young Justice season 4 and why the 31st century Legion of Superheroes might feel the need to send at least one of their members back in time to the 21st century. Given the difficulties and dangers involved in traveling through time in the DC Universe, it seems unlikely that the blonde woman has traveled alone or that she was just infiltrating the party to see the legends of her era on a day off. Indeed, there is a good chance that the lion's share of Legionaries may have traveled to the past to avert some great disaster.
The Legion Of Superheroes Explained
The Legion of Superheroes first appeared in Adventure Comics #247 in April 1958. It was here that a teenage Superboy was first confronted by Lightning Boy, Saturn Girl, and Cosmic Boy, who claimed they had come from the future to see if Superboy, who was a legend in their time, was worthy of joining their team. After running through a series of contests against the other Legionaires and proving unable to win a single one, Superboy expressed his disappointment to the trio of teen heroes. The amused Legionnaires revealed that he had already been unanimously voted into the Legion of Superheroes and that they had just run Superboy through the same friendly hazing ritual of rigged contests they arranged for all their new recruits.
While they were originally meant to appear in a single one-off story, the concept of the Legion of Superheroes resonated with readers and inspired a considerable amount of fan mail asking for more stories featuring them. The team returned nearly two years later to guest-star in another Superboy story in Adventure Comics #267 and began to appear in a regular monthly feature, starting with Adventure Comics #300 in September 1962. Eventually, the Legion of Superheroes all but took over the Adventure Comics anthology, with the adventures of Superboy and the Legion coming to focus on just the Legion.
The precise details behind the Legion of Superheroes' structure and their reality would be fleshed out during this time. Based on Earth, the Legion was revealed to be one peacekeeping force among many protecting the United Planets, alongside the Science Police. The leadership of the Legion rotated on a regular basis through all its members and they had a unique rule in which every member of the Legion had to have at least one superpower that no other Legion member had. However, this rule seemed to be ignored in the case of those heroes like Superboy, who had multiple superpowers shared across the Legion's membership.
The Legion of Superheroes' Core Members
While the membership of the Legion of Superheroes has changed several times over the years as the team has been rebooted and modernized, a certain core membership has remained constant as the heart of the team. The three original Legionaries from the team's first appearance - the magnetic Cosmic Boy, electricity-manipulating Lightning Lad, and psychic Saturn Girl - are usually portrayed as the founders of the team. This was the case in the 1994 Legion of Superheroes reboot, where the three teenagers separately stumbled across an attempt to assassinate industrialist R.J. Brande and used their powers to protect Brande and capture his attempted murderers. An impressed Brande sponsored the Legion financially and pushed to have them recognized as a legitimate law-enforcement organization by the United Planets.
After the trio stopped a terrorist attack on a United Planets meeting, young people from around the galaxy flocked to join the Legion of Superheroes. These included the super-intelligent Brainiac-5, the precognitive Dream Girl, the shape-shifting Chameleon Boy, the self-cloning Triplicate Girl, the super-sized Colossal Boy, and the size-changing Shrinking Violet. Depending upon which version of the Legion was currently canon, their membership has also included XS, the super-fast granddaughter of Barry Allen (aka The Flash) and Spark, the twin sister of Lightning Lad, who also used the codename Light Lass when her powers became altered to give her the power to manipulate gravity.
Why The Legion in Young Justice Season 4 Is Important
If the Legion of Superheroes has seen fit to travel back to the 21st century, it can only be for the most dire of reasons. The technology to travel through time in the 31st century was devised by Brainiac-5 and the typically humorless Brainy (as his few friends call him) would never allow his life's work to be used for anything less than the end of the world as they knew it. Even ignoring the problems that might be caused by accidentally altering the past, it is, from Brainy's point of view, a frivolous use of his technology to take a vacation in the past.
Putting aside the issue of what specific disaster might send the Legion of Superheroes back to the past, the scene at the end of Young Justice's season 3 finale also raises the question of who the mystery waitress is. The smart money suggests that it is Saturn Girl, because she is a blonde who frequently wore her hair in a pony tail. Plus, her telepathic powers would give her the best chance out of all the Legionnaires of blending into a strange time without being noticed. It is also worth noting that Saturn Girl has been lost in the past before, in the comics, most recently in the Doomsday Clock miniseries.
Another possibility is that it is Supergirl, who has yet to be introduced into the reality of Young Justice. Is it possible that Superman's cousin is still out in space somewhere, destined to be discovered in the time of the Legion of Superheroes? Or will Kara Zor-El appear at some point in the not-so-distant future, traveling forward in time to join the Legion before the heroes of the modern day meet her for the first time? Anything is possible in a place like the DC Universe, where the possibilities are as infinite as the Earths.