Now on his own, Ben sets out to be a solo superhero, with new alien heroes at his disposal, but Grandpa Max has other plans. (Introducing Rook, Malware, Khyber, Nemetrix alien Crabdozer, new Ben aliens Feedback & Blox, Pakmar)
Ben and Rook discover an underground city beneath Bellwood populated with aliens! But who is terrorizing them? (Introducing Nemetrix alien BugLizard, & Ben alien Shocksquatch, Psyphon, Fistina, Bubblehelmet, Liam)
Flashback episode: Young Ben, Gwen, and Grandpa Max visit Azmuth on Galvan Prime. There, they have their first encounter with Malware, a corrupted Mechamorph who's determined to make Azmuth cure him, by any means!
Ben and Rook must stop a giant rampaging alien from destroying Bellwood while dealing with a peace-loving alien-rights activist who doesn't want it hurt. (Introducing Hokestar, Solid Plugg 1st appearance, Pax, Sunder)
When Ben and Rook investigate a mysterious alien ghost ship, they discover that Argit and the Vreedle Brothers are fighting for possession of a doomsday device!
Khyber and his Nemetrix possessed pet have been testing Ben's skills and gathering information. They now use their collected knowledge to finally face Ben in battle.