The series begins five years after the summer vacation when Ben discovered the Omnitrix. It has been removed by Ben of unknown… reasons. A teenage Ben regains the Omnitrix while searching for his grandfather, who was abducted by a xenophobic alien species called the Highbreeds, along with the DNA Aliens at their command, are determined to cleanse the Earth of human beings. Ben’s age causes the Omnitrix to reboot itself, granting him access to a new set of alien forms along with a few of his previous forms. Ben is joined in his search by his cousin Gwen and former enemy, Kevin Levin, as they fight the Highbreed’s universal extermination plan. Later on in the series, Ben yet again goes face to face with villains from his past.