"Gemini," the previous episode, is essential viewing to follow the plot of "Persona," since we know, but Lana doesn't, that she's living with the Phantom, Bizarro, a clone of Clark, as we quickly see when he's exposed to sunlight, a lethal force for him/it. Lana believes she finally has what she has always wanted - a loving and committed "Clark," ready to whisk her off to Europe. But happiness does not last long in Smallville.
Another plot follows up on Grant Gabriel's shocking discovery in "Gemini" that he is a clone of the deceased Julian Luthor. He blows in to see Lionel, with paternity papers, even though warned by Lex to avoid seeing him, but Lionel responds not with threats, but by calling him "Son." Homeless men are being murdered in Metropolis, and Bizarro is allegedly helping Lana track the murderer, the Brain Interactive Construct. Lana has traced the home base for the killer to the notorious Suicide Slums in Metropolis. That night, Bizarro comes to the area, finding Milton Fine/Brainiac, who's busy rat-killin'. Brainiac refers to him as a failed lab experiment, but why would a wraith prefer cohabitation with a human female? And why is Fine in poor condition - he's just a blob of liquid metal? He refers Bizarro to another Kryptonian-on-Earth, ex-scientist Dax-Ur, to help with the sun-sickness problem, but first he must find a beacon device to lead him to Dax-Ur.
Biz comes to see Chloe, looking for the kryptonian scientist, lying about the source of his information, and asking about a device. It's a shield, Chloe says, but of course Biz does not know of this object or it's location as Clark does. He gets pushy, out of character for Clark. He demands she tell him the location of the shield, but good ol' Chloe already smells a rat, and puts him off the trail.
At the mansion, Lex wants to ask Lionel about Grant's latest visit. Lionel does not reveal he knows about Grant being a clone, but Lex guesses it, and Lionel scorches Lex's depraved act in recycling his dead brother. "It's you I've lost," Lionel says, striding out. Chloe comes to the farm to tell Lana about Clark's unusual behavior, but Lana sees only that Clark has become more understanding. It's that old "He's not himself" story, when Bizarro comes in the front door (Continuity problem - he was out in the sunshine), dropping the news that he and Lana are leaving Smallville. Lana is depicted as naive here, overcome with the happiness that she feels is finally hers, and Chloe marches out. Biz deflects Lana's concern by suggesting that Kara took the shield.
Bizarro flies to the Fortress in moments - wearing a red shirt and a blue jacket, calling for Jor-El. This seems a bit of a superfluous scene for Biz; apparently it's an excuse to activate Jor-El and have him free Clark from an icy imprisonment. Clark is back in at the farm in seconds, but still no one questions "Clark" wearing a red shirt and blue jacket one moment, while Clark is wearing a blue shirt and red jacket. He has difficulty convincing Lana that the other him was not him, and Bizarro overhears this discussion.
Clark returns to Lionel's office to tell him that he has been trapped in the Fortress. Lionel tells him that blue kryptonite is the only thing that will destroy Bizarro. Again he send Clark to the Dax, who came to Earth a century ago, then vanished. Clark has retrieved the shield, which, when activated, serves as a beacon to the owner, but he does not know how to activate it. Lionel, showing surprising knowledge of all things kryptonian, explains that it is voice-activated. Another surprise identity - Lionel then morphs into Brainiac, a feat which was a strain even for him, and only then do we realize that Brainiac has sent Clark after Dax with the intention of following him. It's incomprehensible why he told Clark about the blue kryptonite, which will eventually be the means of destroying Bizarro. We can only conclude that Brainiac cares not whether Bizarro survives or not.
Clark tells Chloe that he has been trapped, but Chloe is skeptical about which one of the Clarks is genuine. She is wary, but he has a convincer - the yellow sun - he steps into the light, relieving Chloe's fears and anxiety. Saving the day once again, Chloe has, with considerable forethought, taken the shield from the Kent barn.
"Dax-Ur," Clark calls, and is instantly transported to the Arizona desert, finding the scientist in an auto shop under an old Ford pickup. The kryptonian is shocked to hear that name, but the name "Kal-El" convinces him. "You always were survivors." he says of the El family. He has blue kryptonite strapped to his wrist, to deter his own powers, to live a simple life on Earth. It was his work that led to developing the Brainiac, which could lead to the destruction of worlds. He could have saved the human race but gave it all up for a human existence. This backstory has some interesting potential, but it's used only in this episode.
Lana, knowing the truth, now sees a reflection of Bizarro in a ray of sunlight, and tries to escape, but Clark arrives at a crucial moment with the blue kryptonite, somehow finding Biz and Lana at Oliver's loft. But here, Biz seems to have a human weakness for her, even though she calls him a monster - he sounds very sincere. A debate ensues, the two vying for Lana, who wavers, saying she was never more in love, and on the verge of going with Biz. At the last moment she slaps Biz with the blue kryptonite, and the Phantom of these past several episodes begins to disintegrate - his last words, "I loved you." Lana has made a difficult choice.
Brainiac appears in Dax-Ur's shop, having traced Clark's movements to Arizona. Brainiac is damaged, and demands repairs, finally probing the mind of Dax and restoring his own programming. That must be the end of the Dax character.
Lex comes to see Grant, firing him from the editor position, angered over Grant's visit to Lionel. "Dad wants to get to know me better," he retorts to Lex. Lex claims to fear for Grant's life, but Grant, although a clone, accuses Lex of only looking out for Lex. The clone declares independence, like a child outgrowing it's needs for parental oversight.
The treachery begins, as Grant and Lionel (he does not call him "Dad") leave a restaurant, Lionel appearing to accept him as a son. Suddenly they are approached by a mugger, who shoots Grant dead, ending Michael Cassidy's part in the Smallville story. With an outstanding musical score, more scenes without dialog show the mugger/murderer contacting Lex with the news that the job is done. Lex the Creator, Lex the Destroyer - but he is not free of the consequences and he screams to the the night sky. That scene did not play as well as the writers imagined - it would have been just as effective to have a tight close-up of Mr. Rosenbaum, who conveys more emotion with subtle changes in his countenance than with broad gestures and yelling. Why? Because the interpretation is shifted to the mind of the viewer, which can be more imaginative than a script feeding us every emotion through overacting or explosions. And Mr. Rosenbaum has shown time and again that he can carry this off.
Clark and Lana are similarly in the shadows of their relationship, realizing that what Lana thought would be, will never be, and Clark cannot return the hope to her. It's another effective series of dialog-free images, an exceptionally dramatic finale of love seemingly coming to an end yet again.
"Persona" is a well-conceived episode, with a solid Smallville story, fine acting all around, and a couple big surprises. No annoying ultra-dark shadow scenes either, and let's all be thankful that the camera-jerking fad has not infected the show's cinematography crew - the cast and director are allowed to create the action. While redemption for Lex now seems impossible, and the Lana - Clark relationship damaged, we never know if these events will carry over the following week. Even if they don't, the death of Grant Gabriel and the destruction of Bizarro are major developments, and this episode is high on the list for all fans to see. Re-run rating B-.