Besides the Advanced and the Enhanced, there is one more generation of students that appear. While the Enhanced are only slightly modified and are mostly still human, the third generation is essentially grown from cells in a lab and combined with technology + robotic wiring. The main villain introduced is of the third generation.
So essentially we have two new additions to the characters, Brooke and Darren. Brooke has figured out that they are third gens and also how to manipulate signals to control other third gens. Darren's chill and whatnot but he can be "activated" to do what Brooke wants.
Brooke's main purpose is to d e s t r o y, unbeknownst to the main characters (once again focusing on Alice/Cody). She especially hates Cody for some reason.