The game focuses around a rogue army of brainwashed Clap-Traps (led by CL4P-TP, Interplanetary Ninja Assassin, the same Claptrap that is seen getting struck by lightning just after the end credits of the main game) who plan to destroy humanity for their mistreatment, along with an army of familiar enemies transformed into Clap-Trap styles (i.e., Crab-Traps, Rakk-Traps, and Skag-Traps). A wide variety of old cast members return alongside new faces.