Ten-year-old Ben Tennyson is finally back from his summer vacation, and his life is a mess! Humiliated by his teacher, harassed by bullies, grounded by his parents, and cursed with a malfunctioning Omnitrix that s vaporizing his homework, Ben jumps at the chance to get away from it all at the Total Alien Immersion training program on the far side of the galaxy. Little does Ben know that total immersion means he can never turn human again. Crashing back to earth and stuck in his alien forms, Ben becomes the target of an all-new evil alien, Mechamorph, engaging in a deadly cross-world battle, where nothing is as it seems.