After Zim watches an old movie where some invading aliens are defeated by some bacteria, he begins to study germs more. However, when he discovers that such germs truthfully are everywhere, he begins a crusade to kill every germ in his headquarters so that he can be safe, which is helped by the fact that Gir had some cleaning spray handy in the house; though when the cleaning bottle runes dry, Zim must attempt to go to the store and get some more, despite the fact that he knows just how many germs are out there.

When Zim’s headquarters are having security problems, Zim attempts to upgrade the security system and get the job over with. He decides to put Gir in charge of ensuring nothing goes wrong while he replaces the computer’s AI, but when Gir begins to mess around with things, he inadvertently causes the house to shut down along with himself. However, Zim soon discovers that Gir’s AI has been uploaded into the central hub of the house, which worries Zim quite a lot since Gir is being unresponsive and uncontrollable, which soon puts their mission in jeopardy.

When Zim is attempting to explain to the Almighty Tallest that the humans are both dumb and tall, he gets interrupted when the doorbell rings and his transmission to the Tallest is cut short. The two individuals at the door claim to be human, but Zim doesn’t believe them and he attempts to tell them that their spaceship is jamming his signal; they respond by merely sacking both Gir and Zim and taking them to their spaceship. Will Zim be able to get back to his base and finish his report to the Tallest, and what will Zim do to the two aliens who dared to capture him?

The Almighty tallest are examining a storage planet in order to send valuable goods to the Invaders to help them on their missions. They decide to send a Megadoomer Combat Stealth Mech to Invader Tenn to help her conquest of the planet Meekrob and they decide to send a box of malfunctioning SIR units to Invader ZIM, but when the two packages addresses are switched by an angry slave, ZIM gets the Megadoomer and plans to use his new gift from the Tallest to put an end to Dib once and for all.

Dib interferes majorly with Zim's plan to bring the Almighty Tallest to Earth just as he's preparing to bring about the downfall of the human race with mind-sucking parasites.

Dib summons Mortos der Soulstealer, a mystical being who emerges once every thousand years, in order to wish for him to steal ZIM’s soul. However, when it turns out that Mortos needs to recharge his power before he can complete the task that Dib requested, Dib must help him do many absurd things in hopes of putting an end to ZIM once and for all. Meanwhile, ZIM heads around town undergoing his latest evil scheme, which is the reason Dib was so eager to enlist Mortos’ help in the first place.

Zim's former boss is mad at him for leaving, so he kidnaps him and makes him work at his old job on the planet Foodcourtia.