After the disappearance of her scientist father, three peculiar beings send Meg, her brother, and her friend to space in order to find him.

Teenager Cleo’s school science project goes quite awry, causing her popular older sister Molly to go invisible.

Eight years after the third film, the OSS has become the world’s top spy agency, while the Spy Kids department has since become defunct. A retired spy Marissa (Jessica Alba)…