On their last day of school, Mr. Sweet announces a trip to an Egyptian Museum and Mara as their Valedictorian. At Anubis House, the newbies: Cassie, Erin, and Dexter have moved in early because of bedbugs in the middle school. While leaving for the museum, Eddie and Fabian meet Sophia. At the museum, Alfie and Willow discuss college but Willow isn't as excited as Alfie. Eddie, Sophia, and Dexter learn about the Touchstone of Ra. Back at Anubis House, Mr. Sweet tells the residents that an exhibit went missing during their museum visit, so Mr. Sweet and Victor conduct a bag search. Eddie reaches into his bag and finds the Touchstone inside.
Mr. Sweet finds the Touchstone and confiscates it. Victor puts the stone in his safe. Mysteriously the lights go out causing Victor and Mr. Sweet to leave the house. The Anubis residents plan a feast in the cellar. In the cellar, Alfie and Jerome scare the others, which causes Willow and Sophia to go upstairs. Sophia goes into Victor's office and the house starts shaking. The Touchstone opens Victor's safe and Sophia claims the Touchstone and her revenge on Anubis House.
When Eddie, KT, and Dexter come in, Sophia acts innocent. Eddie takes the Touchstone and hides it. Eddie, KT, and Sophia go back to the cellar through the secret passage. When Victor and Mr. Sweet come back, they hear noises in the cellar and investigate. Everybody hides when they hear Victor. Victor and Mr. Sweet find some of the students. Victor explains that when the Pyramid of Ra is built a human sacrifice must be made and that the other stone pieces are buried in the grounds. After they leave, Sibuna talk about the Touchstone and Sophia is welcomed into Sibuna. Mara starts to get suspicious but their conversation is cut short when Victor comes back into the cellar. Meanwhile, Joy, Jerome, and Willow, prepare the Graduation and Prom. Back at Anubis House, Dexter catches Sophia sneaking out of Eddie's room. Victor is trying to find the other stones. Dexter follows Sophia and sees her with the Touchstone. Eddie finds out the Touchstone is gone and blames Dexter when he comes in. Dexter tells them to ask Sophia but Eddie doesn't listen and tells him to leave when Sophia arrives. Sophia continues to act innocent around the other Sibuna members. Mara comes in and show them coordinates on a piece of paper she took from Victor's journal, this lands her a spot in Sibuna. Later that night, Sibuna have a dig and find a Canopic Jar. After Mr. Sweet catches and punishes them Sophia runs out and Eddie goes after her. Back at Anubis House, Eddie finds Sophia with the Touchstone and she gives up her identity. Sophia explains that all it took was a few bedbugs, a forged invitation, and she thanks Eddie for bringing in the Touchstone for her. Dexter momentarily distracts Sophia giving Eddie a chance to snatch the Touchstone and runs. Eddie smashes it but it pieces back together and knocks him out (or Sophia thinks it does).
Sophia reclaims the Touchstone and possesses Dexter who came in behind her and orders him to get her the Canopic Jar. When Sophia turns back around Eddie is gone. Eddie follows Dexter and causes the Canopic Jar to smash after he tackle him. Eddie follows him to Frobisher's Crypt. At the crypt, Sophia tries to possess him but can't and learns he's the Osirian. Sophia leaves the crypt, trapping him and Dexter who is no longer possessed. The Remaining Sibuna Members go to the school. Alfie ask Willow whats going on, she says she can't go to the same college as Alfie because she needs an extra credit in Business Ed and she decided to help with the decorations but she forgot to order the Valedictorian Medal for Mr. Sweet. So Alfie decides to help her. At the school, Fabian and Mara see the Canopic Jar broken in pieces. Fabian sees Hieroglyphics on the Jar pieces and studies them. In Mr. Sweet's Office, KT and Alfie learn that Sophia has been enrolled in the school many times before. Back at Anubis House, the girls get ready for the Prom. Later, Cassie, Erin, and Sophia come help with the decorations hoping to get an invite to the Prom. KT notices Sophia has her key and thinks Eddie is in the crypt. Patricia gets it back for her. Fabian tells the others that when the sacrifice is made whoever held the Touchstone turns to stone.
While leaving to rescue Eddie, Alfie finds a dirty coin and thinks it could be used as a medal. After rescuing Eddie, they split up. KT and Eddie search Sophia's room for the Touchstone and the others search for the other stone pieces in the school. KT finds the Touchstone when Sophia comes in. Eddie and Sophia fight for the Touchstone. Victor arrives and wants the Touchstone. Eddie doesn't give it to him and run. Chaos goes throughout the house. The Touchstone traps them but Fabian rescues them and Sophia runs after them. Meanwhile, Dexter explains to Erin and Cassie that whoever touched the Touchstone turns to stone. Mr. Sweet finds out Willow didn't order the Valedictorian Medal, which means she won't get her extra credit. Victor helps Sibuna find the other stone pieces. Victor and Fabian check out the Canopic Jar again. Alfie finds Willow and gives her the dirty coin he found. After Willow cleans it he sees the Symbol of Ra on it and tries to get it back but let's her have it. Dexter, Erin, and Cassie follow Eddie and KT into the woods. Eddie gives the Touchstone to KT and welcomes Dexter, Erin, and Cassie into Sibuna since they'll be staying in Anubis House the next term. After he's done, they can't find KT and the Touchstone anywhere. Meanwhile, Victor and Fabian learn that the sacrifice must wear the Symbol of Ra. Alfie tells Mara about the coin with the Symbol of Ra on it. Everyone gathers in the main hall and Mara knows where the other stone pieces are. Everybody goes to the graduation except Eddie and the newbies. Before, she leaves, Patricia gives Eddie one last kiss. They help Victor search for the other stones in the cellar. At the graduation, Mara tell the others about Alfie's coin but they see Willow give it to Mr. Sweet. Then, the graduation starts. Sophia goes back to Anubis House and summon the other stones which causes the house to fall. Eddie keeps it standing using his Osirian Powers and knows where Sophia is. Mara is awarded the Valedictorian Medal and Fabian sees the Symbol of Ra on it. Fabian remembers that the sacrifice must wear the Symbol of Ra and he rushes to the stage to get it, but fails and leaves with the other Sibuna members. Mara wears the medal and is possessed causing her to walk off. Meanwhile, Sophia has completed the Pyramid of Ra. KT is Sophia's chosen sacrifice but Fabian tells her it won't work because she isn't wearing the coin. Sophia stops KT. Fabian tries to block Mara but fails. Eddie grabs the coin and it comes off causing Ra to rain down his anger. Victor explains that the Osirian must give up his powers to save the world. Eddie claims the gold and stops Ra but faints. Now he is a normal boy. Afterwards, they have a proper Graduation and attend the Prom. Victor decides to leave Anubis House and keep the Touchstone safe. Before Victor leaves, all the Anubis Residents gather to say a final good-bye to him. Back at the Prom, everybody is happy. Mara and Fabian share a kiss. Patricia ask Eddie to dance and he agrees. The camera angles to show the "Anubis House" banner.
