The episode starts with the Xiaolin monks fighting and beating Jack Spicer's new robots, the Cheer-bots. Then a meteor comes and hits the temple grounds, revealing a message from old Omi. He says that evil has taken over and that the only way to stop it is with the Sands of Time.
After Jack goes, Omi and gang are told by Master Fung that the Sands of Time is a Shen Gong Wu that allows the user to travel in time. Therefore, Omi and company fly around the world searching and see a pyramid with the title "Sands of Time". It then cuts to Jack and Wuya and she senses the Sands of Time. Dojo then senses the Sands of Time but cannot fly so they take a jet plane. After the plane they arrive back at the temple, but when they enter they see Jack Spicer with the Shen Gong Wu (it was hidden in the temple). Jack goes to his home and he praises himself and uses the Sands of Time. He arrives at the dinosaur era and realizes he went too far back and travels in time collecting the strongest baddies. After the Xiaolin Warriors leave, Jack comes back presenting to Wuya old Jack (very old Jack). Dojo and co are flying and he lands with where the new Shen Gong Wu, the Sweet Baby Among Us, should have been. They see a card from Jack and wonder why he was there so fast. They see him with old Jack and listen to their conversation and find out they have to get the Ruby of Ramses. Dojo says he saw it in the Sands of Time theater and they fly back to Egypt. The director gets angry with them, Jack comes, and they start fighting. Omi runs off using the Shroud of Shadows and takes the Sands of Time. He and old Omi arrive and touch the Ruby of Ramses at the same time as the Jacks, starting a Xiaolin Showdown Tsunami. The Omis wager the Third-Arm Sash and Thorn of Thunderbolt against the Mantis Flip Coin and Monkey Staff. First to get to the top of the pyramid maze wins.
In the first level, everyone is lost until Jack sees the entrance to the next level. He tries to fly there with his Heli-Bot but fails. The Omis see the Jacks going to the next level and run for the platform, but the ground starts to collapse. Old Omi starts to fall, but Omi catches him with the Third-Arm Sash. In the next level, both teams reach the platform at the same time and start fighting. Old Omi uses the Thorn of Thunderbolt to blast the two Jacks out of the maze. Omi and old Omi reach the top first and win the showdown.
They arrive in the temple and say good-bye to old Omi and the episode ends with Omi saying he knows where old Omi would have hid it.