The episode begins with Zim and GIR plummeting out of the sky in their burning Voot Cruiser, which has been damaged by GIR. Zim is headed underground to the repair bay but sees that a human baby is staring out its window at Zim. Zim, fearing that the baby is a threat to his mission, sets out to interrogate it, disguised as a “neighborhood baby inspector.” After a hopeless attempt at getting information, he is warded off by a horrible smell caused by the baby. He is then in his base when the doorbell rings. When Zim goes to see who is there, (nobody is), he discovers a group of babies in strange uniforms. He then finds out that they are extraterrestrials that have been left on Earth for seven years (when they were accidentally swapped with human babies during an information-gathering mission at an Earth hospital.) The babies then try to steal Zim’s ship, but Zim makes it to the repair bay before them and finds GIR messing with the power amplifer, creating a field that emits stupidity on whoever is near it. Zim is able to stop the babies by using the power amplifier on them and pass them off as human babies once more.