The cover illustration features a mummy coming out of the tomb steaming.
Gabe Sabry is flying back to Egypt to attend the grand public opening of the pyramid Uncle Ben was excavating in the last book. Uncle Ben and his daughter Sari pick Gabe up from the airport and they drive straight to the pyramids in Giza. Uncle Ben informs Gabe that instead of a hotel in Cairo, they will be staying in the Pyramid Hilton, his name for the tents lining the exterior of the pyramid.
Uncle Ben announces that he and his team are very close to breaking the seal on a tomb inside the pyramid. As Uncle Ben walks the children to the pyramid's entrance, a mummy staggers out and attacks the three. Except it is not really a mummy at all, but a guy dressed as a mummy making a commercial for "Sticky Bird Bandages."
Uncle Ben gives Gabe a necklace with a pendant made of amber. Inside the amber is a scarab, which Uncle Ben explains were sacred insects to their ancestors. Sari thinks it is a dumb present, but Gabe wears it with pride. Sari tells Gabe that the scarab beetle somehow came out of the amber and is crawling on him. Gabe feels a pinch on his leg and remembering that Uncle Ben warned him that a scarab bite meant instant death, he falls to the ground howling in horror. Except that the scarab never left his pendant and the pinch came from Sari, who knelt down and pinched his leg. Gabe is upset, but Sari feels she should not apologize.
Over breakfast the next morning, Uncle Ben tells Gabe about the tomb they are opening. Ben believes it belonged to King Tut's cousin, Prince Khor-Ru, and could be filled with millions of dollars' worth of valuable jewels. Or it could be empty, a trick tomb to fool grave-robbers, Ben casually warns. After breakfast, Sari tells Gabe that she is worried about her father. He is really set a lot of his hopes on the discoveries inside the tomb making him famous and she is afraid that he will be really depressed, if there is nothing inside the tomb.
Uncle Ben hurries over to the children and drags them into the pyramid, as his workers are ready to break the seal. He gives the children yellow hard hats with lights to wear. The three don't make it very far inside the pyramid, before they are stopped by a beautiful woman dressed in a white pantsuit. The woman introduces herself as Nila Rahmad. Nila is a reporter for the Cairo Sun and she wants permission to accompany Uncle Ben as he opens the tomb. Ben consents, as she claims to have run this idea past Ben's partner, Dr. Fielding. Nila asks Sari and Gabe, if this is their first time to be in a pyramid and Gabe says it is.
Nila admires Gabe's pendant and shows him her matching necklace-- only hers doesn't have a scarab inside. Ben tells Nila a bunch of stuff about the pyramid in a clumsy attempt to impress her. Gabe complains that it is cold inside the pyramid and he should have brought a sweatshirt.
Almost immediately, Gabe gets lost and does not know how or why. Gabe stops wandering the tunnels of the pyramid and leans against a wall. He then leans through the wall as he tumbles into yet another secret hidden chamber. Inside this chamber are thousands of white spiders. The spiders swarm over Gabe, as a rope ladder finds its way down into the room.
Uncle Ben and Nila hoist Gabe back up and Gabe takes out his mummy hand to make sure it survived his fall. Gabe is shocked when Nila asks him if it is The Summoner. It figures that the one character who would remember anything about the previous book wasn't even in it. As the other characters turn around to make their way back on course, Gabe looks down at the mummy hand and sees the fingers twitching.
Two days later, Ben's workers finally prepare to break the seal to the tomb. Ben gathers up the two children and Nila and they head down the pyramid. Ben prepares to chisel away the soft gold seal, when he hears a booming voice: "PLEASE- LET ME REST IN PEACE!" They all turn around and see a lanky man. The man crying out is Dr. Omar Fielding, Ben's partner. Dr. Fielding tries one last time to reason with Ben, to not break the seal. Dr. Fielding reminds Ben that the hieroglyphs on the door warn that anyone who repeats the ancient chant written on the door five times will return the mummified prince to life. Dr. Fielding refuses to be privy to incurring the mummy's wrath and flees the pyramid. Ben chisels away the seal and pushes open the door. Unfortunately, the inside of the tomb is completely bare.
Undeterred, Ben makes the entire crew enter the bare tomb and begin work on removing the gold seal off of another door found in the room. After working all day, the workers remove this seal, and behind the new door they find a large mausoleum filled with pots and chests of treasure. The tomb appears to have once been a meeting room, as inside they find a long table, chairs, and a large throne. The attention of everyone in the tomb soon turns to the stone casket resting against a far wall. Ben and three of his workers slowly lower the coffin to the ground and slide off the lid. Inside they find the tar-stained, mummified body of Prince Khor-Ru. Suddenly four men burst into the tomb, waving guns. They announce themselves to be with the Cairo police. Dr. Fielding saunters into the tomb and tells Ben he changed his mind and called the police to come and guard the tomb's treasures. Ben wearily accepts the help of the police, as he has no choice.
That night, Ben, Nila, and the children are eating dinner around a campfire in the desert. Nila has her arm wrapped around Ben and wants him to tell her the six words that will bring the mummy to life. Ben finally gives in and reveals them to be "Teki Kahru Teki Kahra Teki Khari." Ben scurries away to do some work in the communications tent and Nila heads back to her office in Cairo. Back in their tent, Gabe comes up with a plan to scare Sari, to get her back for all her pranks. He recites the correct chant five times and Sari is visibly disturbed.
A gruff figure accosts the children in their tent but it turns out only to be Dr. Fielding. He tells the two youths that he must find Ben and the two children decide to follow him for adventure. As they watch from a safe distance, they can't tell whether Dr. Fielding is leading Uncle Ben towards the pyramid or just resting his arm on his shoulder as they walk quickly across the sand. Dr. Fielding appears to push Ben down into the pyramid's entrance and the two children agree that since they do not have flashlights, they will have to wait outside the entrance. Gabe tells Sari that he saw the four policemen leave earlier in the afternoon, meaning that Dr. Fielding and Ben are alone in the pyramid. After waiting about an hour, Dr. Fielding emerges, alone, from the pyramid. The children try to catch his attention, to ask where Sari's father is, but Dr. Fielding just runs away into the night. Gabe tells Sari to stand guard at the entrance in case her father comes out while he runs back to the tents to grab some flashlights. When Gabe returns, Sari signals that Ben did not come out. The two children head into the dark pyramid, alone.
Sari can't remember the exact route that leads to the prince's tomb, but Gabe spots work boot prints in the sand and the two follow the tracks into the empty tomb. They see no sign of Ben, until Gabe notices that the lid to the mummy's casket was now closed. It was open when they had left earlier in the day. The two slide the lid off and find Uncle Ben tied and gagged inside. Dr. Fielding had left him to suffocate sealed inside the casket. Gabe and Sari realize at the same time that if Ben's in the mummy's coffin, then where's the mummy? Right at the entrance to the room, and he is heading right towards the children!
Gabe tries to yell for his uncle to save them, but he's passed out inside the case. The two children maneuver their way past the mummy and into the empty room. They run right into Nila. They plead with her to help them, but she gets angry at the children and tells them that they've ruined everything. Nila produces Gabe's mummy hand, which she stole from him, and uses it to call the mummy closer. She reveals that the mummy is her brother and she is over 4,000 years old. Now, thanks to Gabe's Summoner, she and her brother can reign over Egypt again.
She calls on her brother to kill the children, but the mummy walks right by them and instead starts choking his sister. "Leave me in peace," the mummy groans as he assaults Nila. Gabe tries to break up the mummy murder and accidentally pulls off Nila's amulet. It crashes to the ground shattering into a thousand shards. She howls out and tells Gabe that the pendant was how she stayed alive all these years. At night she would revert into a scarab and climb inside the amber. Nila shrinks down into the scarab beetle and scurries away into the dark pyramid.
Dr. Fielding bursts in, surrounded by police. Turns out Dr. Fielding was not forcing Ben into the pyramid earlier, he had just seen Nila trespass inside and wanted help in stopping her. Then when he ran to get the cops, he was so frantic that he did not bother to stop and reassure Sari. Well, that's the end of that caper, gang.
Back inside their tent, Gabe is bragging about his accomplishments to get back at Sari. Sari jokingly warns that Nila, the scarab beetle, could still be after him and he should look out she says "Watch she will be waiting for you under your covers." Gabe climbs into bed and utters in horror "Ouch."
- This is the only Mummy sequel to date in the series, and the first sequel to have an original title, previous sequels had all had the same title as their predecessor with the Roman numeral II added.
- This is Gabe, Sari and Ben Hassad's last appearances to date.
- This book contradicts The Curse of the Mummy's Tomb several times:
- Gabe says to the reader that he visited the pyramids during the previous summer. The prequel says that Gabe visited the pyramids during Christmas vacation.
- During the celebration scene, Gabe tells the reader that Sari loves being taller than him even though he is older. In The Curse of the Mummy's Tomb, Gabe says that Sari was two months older than him.
Both Prince Khor-ru and Nila Rahmad appear in the Goosebumps film as background monsters.