Much like between the first two seasons, there will be a time jump with a lot of changes being put in place for the team, the Justice League, and their allies. One of which will see Kaldur'ahm being elevated from his role as Aqualad, to taking on the mantle of Aquaman.
"We established back in Season 1 that King Orin was training Kaldur to take his place as Aquaman," producer Greg Wiesman said to Entertainment Weekly. "Aquaman was also King of Atlantis, which to most people would be a full-time job, and yet he also had to be in the Justice League as Aquaman, which was a lot on his plate. His game plan was to train Kaldur’ahm to be the new Aquaman so he could go back to being King of Atlantis, which was plenty.
"What you’ll see in this season is that after everything that’s happened in Season 1 and Season 2, and the leadership qualities that Kaldur has shown, Orin looks at Kaldur and says, ‘You’re ready.’ It’s a pretty momentous year for him."
The new episodes of Young Justice are embracing the status quo established in the first two seasons of the series, showing a world in fear after metahuman trafficking rings embroil the planet in intergalactic conflict. This affects the new generation of superheroes who come under the tutelage of Aquaman and Nightwing.
"What’s great about those characters is they’re young characters who are now growing up in a world that is formed from our first two seasons," producer Brandon Vietti added. "We really had a heck of an arc through our first two seasons. We explored how society viewed heroes, and how aliens came to Earth to harvest the metagene that powers many of the superheroes and villains.3comments
"When we came back to start our third season, we were looking at this world we’ve created and watched grow through the first two seasons and we’re like, ‘Wow, this is a really scary Earth. What must it be like to grow up on this scary place that we’ve built up through two seasons?’ We decided to tell that story that through this new young group of characters who are growing up in this crazy, scary world, and they don’t know if they want to be heroes, they don’t know if they want to be villains, they’re very much finding out who they are. They’re not part of a superhero establishment like our Season 1 and 2 characters were. They’re figuring out their own way in the world."
Young Justice: Outsiders premieres on DC Universe on January 4, 2019.