Archaeologist and adventurer Rick O'Connell is now married to Egyptologist Evelyn, with whom he has an eight-year-old son, Alex. The family's discoveries link them to the bracelet of Anubis, which once belonged to the Scorpion King, a mythic warrior who made a pact with the god Anubis to raise an army to conquer the world. The bracelet is said to lead to the Scorpion King's resting place and his legendary army. When Alex inadvertently triggers the bracelet’s power, the O'Connells are thrust into a race against time to prevent the awakening of the Scorpion King.

Meanwhile, the ancient and malevolent mummy Imhotep is resurrected in London and seeks the bracelet to achieve his goal of defeating the Scorpion King and harnessing the latter's army to rule the world. Imhotep's followers kidnap Alex, forcing Rick and Evelyn to chase them across the globe to rescue their son and stop these ancient forces from unleashing chaos. Their quest takes them from the British Museum to the Sahara Desert, rekindling old alliances and facing new foes along the way.