Ben and a mysterious girl from his past must prevent an alien threat from destroying the world.

Ryan Kelleyas Ben Tennyson
Galadriel Stinemanas Gwen Tennyson
Nathan Keyesas Kevin E. Levin
Alyssa Diazas Elena Validus
Herbert Siguenzaas Victor Validus
Barry Corbinas Grandpa Max Tennyson
Dee Bradley Bakeras Big Chill / Humongousaur (voice)
Alex Winteras Nanomech (voice)
Wendy Cutleras Alien Chip Queen (voice)