Alvin ist überzeugt, dass sich im Keller seiner Schule Aliens aufhalten. Als Theodore verschwindet und auf seinem Bett grüner Schleim gefunden wird, glaubt er, dass Theodore von Aliens gekidnappt wurde. Mit Hilfe von Simons High-Tech-Ausrüstung wollen die beiden ihren Bruder retten. (Text: Super RTL)
After Alvin annoys his teacher enough so he can get out of detention early, he sees Brittany go into the school's basement. When he takes a peak, he sees a green light and is convinced an alien is inside. At home he tells Simon who doesn't believe a word of it. The next day Alvin confronts Brittany, who spills nothing, and rushes back to the basement at the end of class only to find a neon-green substance on the floor. Simon analyses it and determines it's silicon-based. Despite Simon's request that he drop the matter, Alvin wakes Simon up and forces him to go back to school where they are caught snooping by a security guard. They run home to find Theodore missing so Simon reveals his secret jet packs. Back at school, they see a UFO which, in reality, is part of a movie set they crash onto landing them in detention.
Quand Théodore disparaît en pleine nuit, ne laissant qu'une traînée gluante et verte derrière lui, Alvin est convaincu que des extra-terrestres l'ont enlevé...
Alvin különös fényeket lát kiszűrődni a suli pincéjéből, ezért arra gyanakszik, hogy űrlények vertek ott tanyát. Ráveszi Simont, hogy segítsen neki a nyomozásban.
