"Ten Minutes to Doom" was one of numerous episodes that were not finished by the time of Invader Zim's cancellation.
When Zim's PAK is forcefully disconnected from his body (due to Torque Smackey throwing a dodgeball at him) during recess/break at the Skool, Dib finds it on the ground and steals it, in an attempt to find out what it really is. After failing to stop Dib, Zim reveals that he can only live ten minutes PAK-less. After Dib overhears Zim, he runs away, and Zim goes to get help from a Security Officer at the Skool. As soon as he finds Dib, he is chased by Torque (after Dib told him Zim called Torque a "Dookie Weenie") and manages to escape into town.
Meanwhile, Dib is on the bus for a ride home when he discovers that the PAK has attached itself to his chest. He decides to get help from his father, but suddenly begins behaving like Zim as the PAK accepts him as a new host (Zim's soul essentially fighting Dib's soul for control of his body; more on that later). Meanwhile, Zim finds Gaz playing an arcade game. By this time, he is rapidly deteriorating, to the point where he is barely capable of forming sentences (though he muses that she could help him before his ego momentarily gets in the way ["The sibling. Maybe she could... No! An INVADER needs help from no... helper!"]).
During a discussion with her (in which he addresses her as "Dibsister" for the first time in the series), Zim then abandons his arrogance and bravado, informs her of his predicament and then tricks her into thinking Dib stole her Game Slave 2 and plans to reprogram it (in an attempt to convince her to save him), and an enraged Gaz drags Zim like a rag doll to her house. Thus begins the alliance that forms between them in this episode.
Dib, behaving more and more like Zim (Zim's soul winning the war against Dib for control of Dib's body), finds the Professor building robots named Foodio in an attempt to end world hunger. As Professor Membrane tries to remove the PAK from Dib (upon getting curious over the machine), Gaz and Zim are quickly heading towards Dib's house to get the tools needed for the rescue of Zim's soul. They later get to where the Professor is on a motorcycle, with Gaz threatening Dib to return her Game Slave to her or she'll rip most of his limbs off.
Gaz expertly executes some martial arts techniques on her brother to save Zim. While Gaz is holding off her brother, Zim is dying and - with only 30 seconds left to live - can barely move or talk at all. Dib, under the influence of the PAK and Zim's soul, reprograms one of the Foodio robots, which declares itself to be "Destructio" and flies off to end all life on Earth.
At the conclusion of her one-on-one fighting game-style brawl with her brother, Gaz knocks the PAK off of Dib to help Zim, and, one second short of death, Zim puts it back on with Gaz's help and is rejuvenated, as is Dib. Zim, hubristically forgetting to thank Gaz for helping him, then angrily explains that if he kept the PAK on a second longer, Dib would have died. Zim quickly flees the scene when Gaz sees her Game Slave 2 fall out of his pocket and chases him in a rage, while Dib tries to stop Destructio.
- Gaz once more saves Zim's life unknowingly, the first time being in "Battle-Dib" and the second time in "Mysterious Mysteries".
- This is the first time we see an alliance between Zim and Gaz, though it's a bit rocky at first. However, their actual alliance is only theoretical.
- The way Zim gets rejuvenated with new life energy flowing into his PAK is the same way seen in "The Trial".
- This episode almost became the series finale, with both Zim and Dib dying, thus creating a clean ending. However, Nickelodeon rejected the idea in case the series ever came back (since they knew how much the fans loved it), so "The Most Horrible X-Mas Ever" ultimately became the show's finale. Eventually, the show's return became the case with both the comic book series and the TV movie.