On their fifteenth birthday, the Teenage Mutant Ninja Turtles rise to the surface of New York City with the permission of their sensei Master Splinter. Once topside, the Turtles encounter their first taste of pizza and meet a teenage girl named April. Unfortunately, a robotic menace known as the Kraang abduct April and her father. Now the Turtles must jump into action in order to save the day.

In search of the whereabouts of the recently abducted April O'Neil, the Turtles investigate the base of the robotic Kraang army. Meanwhile, newfound leader Leonardo struggles to lead his rebellious brothers to victory. The Turtles will have to overcome their differences or else leave April and her father in the hands of the Kraang.

Raphael loses his temper when he is insulted by a caustic New Yorker (Vic). The ensuing yelling match results in the Turtles being ambushed by the Kraang and blowing their mission. Worse, Vic caught the whole thing on video, thus raising the frightening possibility of the existence of the Turtles becoming widely known. Raphael must learn to control his rage and endure insults in order to help the others retrieve the video before it falls into the wrong hands.

Michelangelo accidentally befriends Chris Bradford, a henchmen who's secretly working for Shredder!

The Turtles meet a devious inventor named Baxter Stockman. But is this man all that he appears to be?

Chaos ensues when Donatello creates Metalhead, a robotic turtle to fight alongside the rest of the group.

While searching for a missing scientist, Donnie and April find a psychic monkey instead.

Leonardo struggles with his past when an old enemy, Xever, comes back to attack a noodle shop.

The Turtles spring into action when April receives a distressing phone call from her father. Now it's up to the team to stop the Kraang from detonating a bomb in the city.

When their home is attacked by Bradford, the Turtles must step up and defend the only home they've ever known.

The Turtles must divide and conquer when the Purple Dragons and Baxter Stockman team up to introduce a new threat, the mechanical Mousers.

Michelangelo befriends Leatherhead, an unstable mutant alligator who possesses a strange piece of Kraang technology, but the other Turtles aren't sure whether Leatherhead is a friend or a foe.

The Rat King threatens to take control of the city and also Splinter's mind.

Raphael takes charge of the crew while Leonardo gets acquainted with a dangerous female ninja.

Leo and Raph fight over Leo's crush on Karai, and whether or not they can trust her. Meanwhile, the Turtles get their first look at high school when April's school project draws attention from the Kraang.

The Turtles meet their first fan when a teenager decides to dress up and fight crime as "The Pulverizer."

While breaking into the hostile environment of TCRI headquarters, the Turtles discover the true intent of the Kraang and resolve to stop the alien invasion once and for all.

A huge, powerful cockroach pursues the turtles as they attempt to sabotage a Kraag invasion scheme.

Baxter Stockman seeks revenge on Fishface and Dogpound as well as the Turtles, and lures them all into a deadly labyrinth.

After witnessing the Kraang in action, Karai realizes the seriousness of the alien threat and proposes an alliance with the Turtles... unless the Shredder finds out.

The Foot Clan attempt to abduct April, who must try to outsmart Karai on her own while the turtles are on an undersea operation.

When Shredder plans to create an army of mutants, the Turtles must rely on the help of the Pulverizer, who was recruited into the Foot (to be expendable) and volunteers to gather information on the inside on their behalf. When he agrees to be a test subject for a stolen supply of Kraang Mutagen, the Turtles rescue him, but not before he recklessly gets himself mutated.

When his brothers fall under the control of a parasitic wasp, Michelangelo has to fight them.

Donatello breaks into a secret Kraang detention center in order to rescue Kirby O'Neil, but ends up trapped inside with a deadly prisoner called the Newtralizer.

The turtles engage in a difficult battle, as they make a desperate assault on TCRI to shut down the Kraang portal.

With the world at stake, the only thing of importance is that the Turtles complete their mission. No matter what ...