The Mummy: Tomb of the Dragon Emperor

In 221 B.C, China is torn by civil war. A ruthless warlord and king named Han rises to make himself emperor of the provinces and unite China. He conquers his enemies and becomes the first emperor of China, The Dragon Emperor. As his first act as Emperor, he orders the construction of the Great Wall Of China, burying his former enemies beneath it and cursing their souls to hold it up for all eternity. The Emperor's mystics teach him supernatural mastery over the Five Elements (Fire, Water, Earth, Wood and Metal). Years pass, and Emperor Han begins to grow fearful that all he has accomplished will be lost upon his death. He hears of a witch, Zi Yuan (Michelle Yeoh), who is said to know the secret of immortality. Han sends his right-hand man, General Ming Guo (Russell Wong), to find Zi Yuan and bring her to the palace. Ming finds Zi Yuan and they fall in love, resulting in jealousy from the Emperor, who desired Zi Yuan for himself. After Zi Yuan supposedly casts the immortality spell on the Emperor in Sanskrit, a language he does not understand, he has Ming drawn and quartered and wounds Zi Yuan. She then reveals that she had foreseen this and has cast a powerful curse on Emperor Han and his army. The Emperor is gruesomely burned alive and imprisoned within a shell of terracotta, as are every last one of his men, transforming them into the Terracotta Army. A wounded Zi Yuan escapes to parts unknown.

In 1946, 13 years after the events of The Mummy Returns, the now-Americanized Alex O'Connell (Ford), son to Rick (Brendan Fraser) and Evelyn (Maria Bello), locates Emperor Han's tomb with the financial backing of Professor Roger Wilson (David Calder), an archaeology professor. There, three assistants are killed by various traps (corrosive gases, arrows and a razor disk). Alex is then attacked by an unknown woman, but succeeds in bringing the Emperor's coffin to Shanghai. Meanwhile, the British government entrusts The O'Connells to take the Eye Of Shangri-La back to China as a good faith gesture to the Chinese. It is revealed that Wilson is in league with a nationalist paramilitary group led by General Yang (Anthony Wong Chau-Sang) and his second-in-command, Choi (Meng), who see the Emperor as the only one who can bring order and greatness back to China. The mysterious woman from the tomb attacks the mummified Emperor in his coffin, which turns out to be a decoy. By accident, the magical fluid within the Eye lands on the statue of the carriage driver, which is revealed to be the actual body of the Emperor. The Emperor is quickly brought back to life, although he remains trapped in his terracotta form (which often chips away, revealing the charred, undead corpse-creature beneath, but quickly reforms as per the curse). Han accepts the service of Choi and Yang but kills Wilson by searing decapitation. The unknown woman from the excavation site tries to kill the Emperor with a magical dagger, the only weapon that can kill him, but is unsuccessful in doing so.

The unknown woman reveals herself to the O'Connells as Lin (Isabella Leong), and agrees to help them. Along with Evelyn's brother Jonathan Carnahan (John Hannah), the group travel to a tower in the Himalayas that will reveal the path to Shangri-La when the Eye is placed on top of it. With the help of three Himalayan Yeti summoned by Lin, the group hold off the soldiers under Yang, but are ultimately unable to prevent the Emperor from learning the location of Shangri-La. He also tries to kill Alex to keep him from starting an avalanche by throwing a sword at him, but Rick jumps in the path of the sword, saving his son. The avalanche triggered by Alex allows them to reach Shangri-La before Han and meet with Zi Yuan. It is revealed that Lin is Zi Yuan's 2000-year-old daughter, rendered immortal due to the power of the magic waters of Shangri-La. The magical dagger which Lin carries is the same dagger that the Emperor used to try to kill Zi Yuan two thousand years ago, with a powerful curse placed on it by Zi Yuan herself. After Lin vouches for the O'Connell's, the ancient witch quickly heals Rick's wound. Zi Yuan also reveals that she would have died if she was not saved by a Yeti. Zi Yuan warns Alex that if the Emperor is allowed to drink from the Pool of Eternal Life, he will not only be able to raise his army, but be granted the power to transform into ancient and fearsome Chinese animal spirits. Alex and Lin have grown attached to each other but Lin pushes the relationship away due to her immortality; after watching Zi Yuan mourn General Ming for centuries, she does not want to fall in love with Alex only to watch him grow old and die.

The Emperor attacks them in Shangri-La and takes the dagger, breaks free of his terracotta form and vows that Lin "will be his", in order to pay for her father's disloyalty. He then bathes in the waters which restore his human form and youth, replenishes his powers, and giving him the ability to shapeshift. He transforms into a gigantic three-headed dragon (a tribute to King Ghidorah), kidnaps Lin and flies to his tomb where he raises the Terracotta Army, now aided by General Yang's soldiers. The Emperor announces his plans to conquer the entire world and that once he leads his army across the Great Wall, an ancient spell will make them invulnerable.

The O'Connells and Zi Yuan pursue the Emperor to the Great Wall where Zi Yuan sacrifices her own and Lin's immortality to revive those buried beneath The Great Wall, creating an undead army of her own, led by General Ming. The Army of the Dead, with aid from the group's modern weapons and limited air support from two World War II-era planes, fights the Terracotta Army while Zi Yuan battles the Emperor, sacrificing herself to steal back her cursed dagger. She is mortally wounded but succeeds in securing the dagger. Then, Emperor Han transforms into a horned Shishi and goes beneath the Great Wall in order to use his elemental powers to negate Zi Yuan's spell and draw Ming's army back underneath it. However, he is stopped by Alex. Yang and Choi are killed by Evelyn and Lin when they attempt to interfere with Rick and Alex. Rick and Alex tackle the Emperor with the dagger but are severely outmatched, not just by his magical powers and transformation into an oni but by his martial arts skills, and the dagger is broken. Rick challenges the Emperor to a fair fight and the Emperor chooses to fight Rick without powers, and Rick manages to plunge the broken dagger hilt into the Emperor's chest while Alex stabs him with the tip of the blade from behind, simultaneously piercing his heart from both sides, releasing the dagger's curse as the Emperor is consumed from the inside out by a fury of molten lava. With The Emperor defeated, his army crumbles and turns to dust. Ming's army celebrates briefly before finally moving on to a peaceful afterlife.

The O'Connells return to Shanghai, where Alex and Lin fall in love again. Rick and Evelyn, and Alex and Lin, share kisses during a slow dance at a bar. Jonathan decides to move to Peru with the Eye of Shangri-La, which he had stolen himself, as there are no mummies in Peru. However, an ending caption appears, explaining that shortly after his arrival, mummies were discovered in Peru.