Mkay, so Splatoon 2: Intergalactic Cephalopods is an alternate reality that takes place after the events of the octo expansion, but what's different about it is that commander tartar used the NILS Statue as a rocket and set of to space. Agent 8 (me) and his 4 friends (you guys) set off to destroy tartar once and for all...

...They eventually run into a group of space pirates who are the last living humans in the universe. Agent 8 and company befriend the last survivors who claim to know where tartar went... And from here, well, you'll just have to wait and see what happens...