12-year-old friends, Marshall, Gilbert and Amy accidentally revive a mummy they discover in a neighbor's basement. They affectionately name the mummy Harold, and must rush to return him to his resting place before midnight on Hallowe

Dora, a teenage explorer, leads her friends on an adventure to save her parents and solve the mystery behind a lost city of gold.

While Amy is preparing for her father's Halloween-themed wedding, she, Gilbert and Marshall discover that Harold and Rose may be in danger. An evil mummy is unexpectedly awakened and out for revenge.