Olivia and her gang of monster friends travel back in time to Egypt to help Mario the Mummy, who is sick with the Nile Fever.

Monstrocity school is celebrating its annual science fair! Olivia and her friends are itching to present their inventions. Vane has even managed to create a time machine!

But what's wrong with Mario the Mummy? He's sickly and pale and in order to cure him, the gang will have to go back in time... to Ancient Egypt! There, they will have to face the three challenges of King Ra. Will the gang be able to pass the tests and save their friend?