In 3067 BC, the Scorpion King leads his army on a campaign to conquer the world. Seven years later, the Scorpion King and his army are defeated and exiled to the desert of Ahm Sher. His men die of heat exhaustion, leaving only the Scorpion King. Vowing to give Anubis his soul for the power to defeat his enemies, an oasis is created to hide the Scorpion King's pyramid and giving him a legion of humanoid jackal warriors to seek revenge. The Army of Anubis sweeps across Egypt, destroying everything in its path, but once their task is finished Anubis claims the Scorpion King's soul and his army.
In 1933, Rick, Evelyn O'Connell, and our heroes explore a ruined mortuary structure in the ancient Egyptian city of Thebes with their son, Alex. They find the Bracelet of Anubis. In London, Alex puts on the bracelet, which shows him a vision with directions to the Oasis of Ahm Shere. Alex has seven days to reach the oasis, or the bracelet will kill him the moment the sun's rays shine on the Scorpion King's pyramid; at that point, the Scorpion King and his army will reawaken.
Evelyn is captured by an Egyptian cult who have resurrected Imhotep; they wish to use Imhotep's power to defeat the Scorpion King, which would give him command of Anubis' army to take over Earth. The cult, led by Baltus Hafez, the British Museum's curator, includes a warrior named Lock-Nah and Meela Nais, the reincarnation of Imhotep's love Anck-su-namun. The O'Connells and our heroes set out to rescue her, accompanied by Evelyn's brother Jonathan and the Medjai Ardeth Bay, the Autobots, Princess Celestia, and Princess Luna.
After having discovered the bracelet is missing, they attempt to kill Evelyn, however a fight ensues between Rick and Imhotep. But Mucker runs out of shotgun shells during the battle, but then Steam Mech finds 3 crates of more shells and then reloads Mucker's shotgun. Imhotep then calls on the help of his mummified soldiers to kill them. After freeing Evelyn they flee on a double-decker bus. During the battle, Mucker uses his shotgun against the soilders but to the team's surprise, his shotgun fires a blue fusion blast and discover that the shells are Fusion Shells. After defeating them, Alex, the CMC, and Stephen are kidnaped and they travel across Egypt to rescue them along with Rick's associate from his past adventures, Izzy, a pilot, who provides the group with transportation. (While Stuingtion's engines also provide the team with a custom airship of their own.)
While stuck with the cult, the CMC and Stephen discover that Starscream is back, he then reveals that Queen Chrysalis resurrected him and Megatron with the Book of the Dead, he also tells them that Megatron plans to kill Princess Celestia while he plans to kill Rainbow Dash. Then they find Wheelie is with them because he jumped on the back of Lock-nah's car and he brought spare Luparas for the CMC.
The bracelet gives Alex visions, directions to Ahm Shere that the cult follows. At each location, Alex leaves clues for his parents, who follow in Izzy's dirigible. (on the way, Willy forges himself a diamond sword) Imhotep uses the Book of the Dead to give Meela Nais the soul of Anck-su-namun but by doing so he allows Evelyn to unlock the memories of her previous life as Princess Nefertiri, the bracelet's keeper and Pharaoh Seti I's daughter. Lock-Nah discovers that Alex has been leaving clues, so Imhotep makes a wall of water that attacks the dirigible. The O'Connells crash in the jungle of Ahm Shere. But before the wave can engulf our heroes, Shiver uses his liquid Plutarium Nitrogen cannon to freeze it. Izzy stays with the dirigible in hopes of repairing it. The O'Connells and our heroes attack the cult, and both groups are attacked by pygmy mummies. Rick retrieves Alex while Willy and Ardeth Bay kill Lock-Nah. They escape from the pygmies, who kill most of the cult except for Baltus. Imhotep and Anck-su-namun are unharmed due to Imhotep's powers and Anck-su-namun being the keeper of the Book of the Dead.
Rick and Alex run to the pyramid, barely making it before sunrise. The bracelet detaches from Alex's arm. Ardeth regroups with the Medjai in case Anubis' army rises. Anck-su-namun stabs Evelyn and kills her. Then Megatron appears and attempts to kill Princess Celestia but Thomas jumps in front of the blast from Megatron's sparing Celestia. Before Thomas passes away, his last words to everyone else is to run. Everyone then sadly grieve over their loss.
Rick, grieving, pursues Imhotep. Princess Celestia, Twilight, Shining Armor, Cadance, Percy, Optimus, and a few of Stuingtion's engines, angered, pursue Megatron, Starscream, and Queen Chrysalis. (Only to discover her Changlings are gaurding.) Stuingtion's engines battle the Changlings, while everyone else goes after the Decepticons and the Queen Changling. Baltus puts on the bracelet and revives the army. As Imhotep walks into the pyramid, Anubis takes his powers, wanting Imhotep to fight as a mortal. Rick finds Imhotep summoning the Scorpion King and they fight. The Medjai engage the army. The Scorpion King interrupts Rick and Imhotep's fight. Imhotep tells the Scorpion King that he is the Scorpion King's slave, but Rick was sent to kill him. During Rick and the Scorpion King's fight, Baltus is killed. Jonathan, Alex, Princess Luna, and everyone else collaborate to steal the Book of the Dead from Anck-su-namun. Alex and Luna use the book to resurrect Evelyn, who duels with Anck-su-namun and then Thomas who joins the battle. In a direct reference to the first film, Alex asks Jonathan for help to decipher a hieroglyph; the same hieroglyph Evelyn had to translate for Jonathan in first film.
Alex, Jonathan, and everyone else go help Rick, the other half of the team while Evelyn fights Anck-su-namun. It is revealed that the scepter that Jonathan has been carrying extends into a spear that can kill the Scorpion King. The Medjai seemingly defeat Anubis' army despite heavy casualties, but see that they have only defeated the vanguard, and the full army is charging towards them. However, before the Anubis warriors hit the Medjai lines, Rick succeeds in killing the Scorpion King, sending him and his army back to the Underworld. The Scorpion King's death breaks his oath with Anubis, causing the oasis to turn back into a desert, and the oasis to be sucked into the pyramid. Rick and Imhotep are hanging from the edge of a pit that leads into the underworld. Evelyn risks her life to save Rick, but Anck-su-namun refuses to do the same for Imhotep, and abandons him. Heartbroken about her desertion, he lets go of the ledge, falling into the underworld, to his death. Anck-su-namun, running away from the pyramid, falls into a pit of scorpions and flesh-eating scarab beetles. Princess Celestia uses the Blue Ruby and the Black Pearl (Relects that Mako found in the preivous film.) to increase her power and then kills Megatron and sends Queen Chrysalis far away, then Scootaloo uses Rainbow's M4 rifle to dentinate an explosive that Mucker placed on Starscream, thus killing him.
The O'Connells and the team reach the top of the pyramid, which is being sucked into the desert. Izzy arrives with a modified dirigible and saves the O'Connells. While the other Planet trains who stayed behind use the custom airship to save the team. Jonathan grabs the diamond at the top of the pyramid. Ardeth Bay salutes them as they fly over him.
- Zecora, Steamy, Puffy, Evan, Shai-Shay, Sharky, Willy (the train), the Miner Trains (Steam Grindor, Steam Mech, Mucker, Steam Claw D., Steam Driller, Steam Sweeper, and Steam Exavator), T.C., Hugs, Buzz, J.J., Socky, Skunky, Mako, 1206, Rattlesnake Jake, Stephen, The Planet Trains (Zip (planet train), Dazzlen, Dusten, Gustis, Rings, Uray, Tune, Shiver), Optimus Prime, Bumblebee, Ironhide, Ratchet, Sideswipe, Dino, Wheelie, Princess Celestia, and Princess Luna are guest starring in this film.
- Megatron, Starscream, and Queen Chrysalis will work with Prince Imhotep in this film.
- The storyline concludes in Ed, Edd, n Eddy vs. The Mummy: Tomb of the Dragon Emperor.
List of weapons used by our heroes.
The movie's cast:
- Colt M1911A1
- Smith & Wesson "Triple Lock"
- Winchester Model 1887 Lever Action 12 gauge shotgun
- Sawn-Off Double Barrel Shotgun
- M1928 Thompson
- Lee Enfield Mk.I CLLE
- BSA Lee-Speed Sporter Rifle
- Gatling guns
- Barrent .50 cal Sniper rifle
- 1928 Thompson Sub-machine gun
- AA-12 Shotgun
- Hand-cranked Gatling gun
- 12-gauge Double barrel Coachgun
Winchester Model 1866 "Yellow Boy"
1896 Krab carbine
.50 cal M2 Browning "Ma Deuce" Heavy Machine Gun
Greener Light Harpoon gun
Lewis machine gun
Boomer .65 cal machine gun
Big Trooper machine gun
Stapler 77 light machine gun
M4 Colt Commando Assult Rifle
12-gauge (short-barreled) pump/SA shotgun
Winchester Model 1912
Remington 1866 Derringer
.38 Smith and Western Revolver
Lupara series (Sawn-off shotguns): Side-by-side, over and under, single shot
- Sulfuric acid launcher
- Flame Thrower
- Steaming Hot Liquid Sulfur cannon
- Liquid Plutarium Nitrogen cannon
Dual Energy Swords
energy rocket launcher
- plasma rocket launcher
- high powered rifles
Small machine gun
Dual arm swords
- The story of the Scorpion King
- Finding the bracelet
- Alex puts on the bracelet
- Museum Shootout/Double-Decker bus chase
- Captured!/Next plan
- Finding the clues to the pyramid/The giant wave
- Battling the cult/retreaving Alex, the CMC, Stephen, and Wheelie
- Race for the pyramid
- Anck-su-namun kills Evy/Thomas' sacrifice
- Battle of the Changlings/fighting the Decepticons and Changling Queen
- Evy and Thomas' ressurection/killing the army of Changlings
- Scootaloo kills Starscream
- Killing the Scorpian King/Megatron's Death/Queen Chrysalis' defeat
- Escaping the pyramid