When does Ben 10: Ultimate Alien return?

Ben 10: Ultimate Alien is the third entry in Cartoon Network's Ben 10 franchise. It premiered on April 23, 2010, on Cartoon Network in the US. The series finale aired on March 31, 2012, with the two-part episode "The Ultimate Enemy" dedicated to series developer, writer, and producer Dwayne McDuffie, who died during the production of the series.