Clark is pondering where to go when a messenger shows up with a package from Dr. Swann. Before he can open it, the news announces that Swann is dead. Swann's message says that Clark must find his father to complete his "mission," and the package has the octagonal key. Clark goes to the cave and uses it, and Jor-El "speaks" to him again, telling him of the three stones and warning that if humans unite the three, the world may very well be destroyed.
Jason calls Lana from Metropolis and says he's overseeing a project for Lex, but it becomes clear he's in China, not Metropolis, and Lex has followed him there, knowing he has the map that Lionel gave him. Lana goes to Lex's manor and meets with Lionel, who helpfully directs her to China and lets her know they're investigating Isabelle, who was tied to Gertrude Teague. Clark goes to visit Lana and after they compare notes, they both go off to China (without Clark telling his parents).
In Shanghai, the local police chase Lex and Jason, who end up getting arrested, tossed in jail, and then Lex is taken away. Clark and Lana arrive and meet up with Lionel's contact, Professor Sen, while Lex returns and Jason is hauled away to be interrogated – Lex has them working with them and tells them to get the info out of Lex, but then they turn against him when someone pays them more.
Clark and Lana get to the temple and Clark spots a secret chamber. He has them leave and then enters it. He finds a ceremonial dress, a mask, and a statue with green kryptonite eyes. Soldiers burst into the temple, kill the professor, and capture Lana, spotting her tattoo. The soldiers are torturing Jason and Lex at the temple for information and bring in Lana and start torturing her. The pain unleashes Isabelle, who fries the guards, breaks free, and reveals that the map is the key.
The soldiers return and take the weakened Clark prisoner, but when they get him away from the kryptonite he busts free. He goes to rescue Clark and Lex, and Isabelle knocks him out and goes back to the chamber. Clark wakes up and frees them and takes them to the chamber. Jason figures out the map show the tree where the stone is buried, and they go after it. Isabelle/Lana is already there and unearths a horse-statue holding the stone. When she breaks it, it gives off the same noise in Clark's head and he super-speeds to grab it. Isabelle/Lana knocks him away and grabs it, but Clark confronts her again and Isabelle/Lana fights him with magically-powered Chinese weapons. She wounds Clark, who puts up a fight against the magically-skilled Isabelle/Lana. Clark manages to get the stone away from her but gets blasted away by Isabelle/Lana. The blast seems to send Isabelle back into hiatus as it were, and the stone disappears.
Later back in Smallville, after a brief conversation with Lana, Clark gets an e-mail from Dr. Swann. Lex has another conversation with his dad who claims ignorance and warns Lex that finding the stones won't ultimately help him. Jason and Lana have another conversation and Jason reveals he has the stone and is holding it for Lana. Clark reveals to his parents that he doesn't have the stone and that Swann told Dr. Crosby to give Clark the one stone she had, but Crosby has disappeared entirely.