In the bad ending of the Octo Expansion, Inkopolis and everyone in it is destroyed, with Cap'n Cuttlefish, Agent 8, Agent 3, and Off the Hook left to pick up the pieces. Struggling among themselves and their inner demons, the New Squidbeak Splatoon must assemble again to face off against new world leader Commander Tartar and uncover more dark secrets of the Kamabo Corporation.