The sidekicks find a clone of Superman known as Superboy. They free him from Cadmus' control, while battling Blockbuster.

After Speedy declines to join the new team, Robin, Aqualad and Kid Flash fear Young Justice is just a big joke…while new member Miss Martian fears there's no room for her to be part of it. So when the four heroes and Superboy come up against Mister Twister, it looks like all their fears have just been realized…

Young Justice goes on its first official mission under Batman, while trying to determine which of them will lead the team.

Green Arrow's niece, Artemis, joins Young Justice and must save a bright young scientist from the League of Shadows.

Young Justice discovers that they have forgotten the last six months of their lives, including each other and a final fateful mission in Bialya. The team turns to Miss Martian to recover their memories, before it is too late for Superboy.

Red Arrow is on his own against the world's most dangerous assassins in preventing the League of Shadows from starting a war, until he is forced to make an unlikely alliance with someone even more dangerous. Aqualad fails to convince Red Arrow to ask the team for help.

Superboy and Miss Martian go undercover inside Belle Reve Penitentiary.

When Mount Justice itself is attacked, can Artemis and Robin (the two teens without super-powers) save the Team (or even themselves) from the unknown invaders?

Already exhausted and rattled after a home turf invasion of The Cave, the team learns that Aqualad - their friend and leader - withheld vital information that put them all at risk. When Batman sends the Team and new "den-mother" Captain Marvel to India to investigate bizarre reports of armed animals attacking human beings, can Aqualad pull his fractured team together?

When Plant Creatures attack major cities around the world, the team is eager to join the fight alongside the Justice League. Instead, Batman assigns them a still more dangerous task - taking out the plants' masters: a secret society of super- villains: the Injustice League!

When the Justice League is defeated during an alien invasion, the Team has to step up and fill their mentors shoes.

It's Halloween. Artemis and Zatanna are in Manhattan for a girls' night out. There, they encounter the deadly Harm, who has a secret.

Wally West comes oh-so-close to fulfilling his birthday wish to finally fight alongside the Justice League. Instead, a massively disappointed Kid Flash is taken off the mission and tasked with a simple delivery job. But a few deadly surprises await the birthday boy along the way.

Superboy returns to Project Cadmus, where he learns the top-secret genetics lab may have created another Super-clone.

The Team goes undercover at the Haly International Traveling Circus to locate a thief stealing weapons technology across Europe. But a thief isn’t all they find…

The Team finally learns the identity of the traitor in their midst, forcing a battle against an enemy more dangerous than any they’ve ever faced before!

Miss Martian, Superboy, Beast Boy and Adam Strange arrive on the distant planet Rann to stop the alien infiltration of Earth at its source.