An alien impersonates Ben with hopes of using his Omnitrix to annihilate him.

Kevin asks Gwen to the school dance; Ben fears he's losing control of the Omnitrix.

Cooper is kidnapped by the DNAliens, who want him to build a mystery arch.

When Ben's parents discover his ability to turn into aliens, they forbid him from using the Omnitrix and later ground him from using it again. Eventually Gwen is grounded too leaving Kevin to stop the DNAliens.

After Gwen receives an S.O.S. from Helen, Ben must go into the Null Void to save her and Manny. Once there, he must find The Wrench in order to stop D'Void, who happens to be Ben's old enemy Dr. Animo

Ben and the gang rescue a runaway prisoner of the DNAliens.

The gang helps the prince of the arachna-chimps regain power

Ben cares for a baby monster and helps locate its parents before the DNAliens find it.

Ben, Gwen and Kevin gather their allies to counter the threat of the incoming Highbreed fleet. Azmuth reveals a secret about the Omnitrix.

Ben goes to the HighBreeds' world in an attempt to stop their attack on Earth.