The girls are sent to investigate the kidnappings of various military personnel and scientists by a mysterious knight. When they end up in the middle of another kidnapping, they follow the criminal through a strange portal, transporting them back to medieval England in the year 1136, 865 years ago. The knight reveals himself as a Malibu teen who wants to overthrow the benevolent king by using his modern technology, and takes Clover as his queen. It is up to Sam and Alex to stop him before the timeline is forever changed. In the subplot, the girls compete against Mandy for the best costume at the annual Halloween dance.