20 Years after the end of Teen Titans, an incident breaks up the Titans. 20 Years afterwards, in a future Jump City, a curious new hero called Nightstar arrives in Jump City, only to find the ruined Titans Tower. She discovers Cyborg, who is now an old man with very little energy keeping him alive, confinded to the Tower. Nightstar learns about the old Titans, and Cyborg tells her to leave him alone, and the Titans in peace. But when a new gang threats to destroy 1/2 of the city, Nightstar finds other Teen heroes like her and assembles the Teen Titans Beyond.
After setting down in the Tower, the Teen Titans Beyond meet the villianous Toyman, who makes an appearance in Jump City with his Hopping Bunnies. However, he seems to have a greater agenda then going the rabbit's hole...
Going Back to 1 year after Calling All Titans, the original team have to fight Blackfire, who has threatened to destroy Jump City if Starfire does not give back control of Tamaran. The Original Team fight Blackfire but it will not be easy when Starfire and Robin begin fighting...
Changer recieves a message from Azarath, saying that his mother - Raven, one of the original members of the Titans needs help. Trigion is invading Azarath, and without help, they will fall. But when the Teen Titans Beyond arrive, can Changer make his mother proud and save Azarath?
While Cyborg is figuring out the location of Beast Boy and Starfire, Mister Twister - a new enemy arrives in Jump City after being hired by the Mammoth Gang. Nightstar and Changer are still recovering from the last battle, Cytech is visiting his mom, which leaves Solstice and Bladestriker. Can they defeat Mister Twister, and what will develop between the two?
Starfire has been found at last, and she's the queen of her home planet. Cyborg sends the team out into space for the first time ever to reunite the Titans, but then Blackfire makes a reappearence. Nightstar joins her mother in the fight againest Blackfire, but she begins to suspect everything is not right...
Mammoths Running About
After learning who her father is, Nightstar is shocked. However, the Mammoth Gang returns once again, only planning to use a formula developed by a company to take control of the city. With Mammoth and his gang fighting the 4 members, Cytech works with Cyborg at Titans Tower to come up with a virius that will neturalize the formula. But when they figure it out before its too late?
Altantis Going Down
Aqualad (now Aquaman - as the original one retired) calls for help in Altantis, as the Mammoth Gang goes underwater for a job. The Teen Titans Beyond go and fight the Mammoth Gang, while Beast Boy turns up at Titans Tower, and confronts Cyborg.
X's and O's
The Original Titans are now 10 Years older since Flashback, and Robin has become Nightwing. The Titans are still fighting in Jump City, but Red X is proving to become a troublesome villian. Nightwing begins to suffer an obbession to defeating Red X like Slade, who has made a few appearences within the last 10 years, but is now missing. This worries Starfire, who has a secret...
T is for Teamwork
Cyborg is becoming worried that the Teen Titans Beyond is becoming arrogrant. One day a simple mission fighting againest the enemy Frog, the 5 titans are seperated into different dimensions. Nightstar confronts her mother, Starfire, Changer faces Beast Boy, Cytech confronts Cyborg's machines, Bladestriker fights Mammoth (a version of him during the Original Titan's time) and Solistace fights Raven. Can they realize Teamwork is the only way to defeat them?
Taking Place a year after the last flashback episode, Cyborg has developed a time traveling machine, with all the Titans wondering if the future seen by Starfire is still the same way 10 years later. However, a bad test makes Nightwing have him shut it down. Only one problem: Red X wants it badly.
The Zookeeper, Part One
In Part One of the Season Finale, Mammoth - tired of the New Teen Titans interference hires a Zookeeper to take DNA from Beast Boy and use it to create a pathogen that will give all of the Mammoth Gang powers. In a fight, Beast Boy's DNA is taken but he is saved thanks to Nightwing - who has returned to Jump City, angry. It is here that Nightwing and Cyborg explain to the current team the reason why they disbanned. But it all goes to a halt when they confront the Mammoth Gang and the Zookeeper, at a price.
The Zookeeper, Part Two
After the accident, the Pathogen is all across Jump city, causing Havoc. In fact, the Zookeeper himself has transformed into a mutation of multiple animals, and defeats the Mammoth Gang. It's up to both the New and Old Titans to defeat the Zookeeper and find a cure before the entire city is in ruins.