"Blue" continues several story lines from a couple earlier episodes, putting some good continuity back in the series. Clark's kryptonian mother Lara appears again, played well and effectively by Helen Slater. Most of the episode is kryptonian-based, with four extraterrestrials battling over the future of the Earth and the El family's destiny. Clark's desire to know Lara leads him back to Kara's blue crystal, which Clark found and hid in the barn in "Lara," two episodes back. The crystal's force calls him to the Fortress, where he defies Jor-El's admonition to put it aside.
Lara's essence - or a replicant - we're not sure what - materializes in the Fortress, and Clark is completely convinced she is real. But activating the crystal also looses Zor-El, Kara's father, and the adversary in this episode. He's played by Christopher Heyerdahl, who comes across as intended - menacing and dangerous. When Clark brings Lara to the farm, Kara realizes that Clark has found the crystal and did not tell her. Lara warns that Zor-El's replicant is right behind her.
And he is, flying into the barn to meet Kara, who is first skeptical of her father's intents, but wants to trust him. In his "Matrix" style outfit, he loses little time in revealing his true ambition - to wipe out the Earth and repopulate it with the descendants of Krypton's survivors. He sends her to the Fortress to wait for him, and then confronts Lionel, who is still Jor-El's vessel, and Mr. Glover's stunt double is tossed across the room, saved only by Clark's intervention. No explanation is given about how Clark knew to come to the Luthorcorp tower at just that moment, and the total screen time for Mr. Glover is about one minute, giving him just enough time to warn Clark that Zor-El is seeking someone named Lara.
The sub-plot is about the budding romance between Grant Gabriel and Lois, but Chloe warns Lois about the appearance that she got her job and assignments based on her relationship with chief editor Grant, not on her journalism skills. Break it off before it breaks her career, Chloe advises.
Clark hides Lara at Oliver's apartment, though she does not fear Zor-El. Replicant-Lara tells him his real mother already died, but Clark is overwhelmed by finally having even an illusion of her. Lana enters too, but gets only a short role in this episode. Lara gives Clark a victory ring from Jor-El, a family tradition, but when he puts it on, his eyes change to "Blue," showing some sort of transformation - and in the next confrontation with Zor-El, Clark finds he has lost his powers. Zor-El throws him onto a Porsche 924, telling him the blue mineral ring was known to have that effect - he knew Lara would give it to Clark . "Your destiny is to rule," he tells Clark, who rejects the offer. But he lets Clark live for Lara's sake.
Back in the tower, Zor-El knocks Lana right out of the episode and takes Lara to the frozen north, leaving Clark to counsel with Chloe, Clark still insisting that Lara is "not a zombie," and believing that Kara betrayed him by revealing Lara's location to Zor-El. Hard to accept that he would believe anything Zor-El said, given his good relationship with Kara. His efforts to remove the ring are futile, until Chloe remembers the octagonal key from the spaceship. He will use this to reach the Fortress, an unseen trip that several reviewers thought was completely unexplained.
A scene with Grant and Lex is very revealing - Lex insisting that Grant break it off with Lois - she's too curious. Grant wants his own life and decisions, but Lex insists. At the DP, they both are ready to end their unprofessional and inappropriate relationship, under pressure from others. Or they seem to be. Wait, one more lip-synch.
At the Fortress, Kara awaits, and only learns about Zor-El's treachery when he and Lara return and he threatens to destroy Kal-El. His plan - begin eliminating those human pests through an artificial eclipse, a nice sun-sky special effect witnessed by Chloe and Clark at the farm. Lara and Kara attempt to end Zor-El's life with Jor-El's dagger, but her attempt is futile, and Zor-El determines to kill Kara. Clark arrives at the Fortress at that moment, with a chunk of kryptonite to disable Zor-El. But he must destroy the crystal and lose Lara in order to save Kara. He shatters it, and is left alone in the Fortress.
Here ends an interesting parallel in this story - both Krypton-expatriates Clark and Kara long so much for their lost parents that they risk their own lives as well as others to have even a chance at a relationship - and with a replicant at that. It's a strong statement about familial bonds in this episode, but their desires are not to be - in fact, both will suffer major consequences for their actions. I see the writers admonishing both to grow up and relinquish the parent-child relationship, and find the love and support they need from among their own. Their past is painful, but they must let go.
Kara's consequences appear immediately - she awakens in the middle of a rain-soaked Detroit street, and through a dialog with a store owner, we learn that she does not know who or where she is. A difficult wet-and-cold scene for Ms. Vandervoort, but played with skill. This creates an amnesia storyline for her for some future episode(s).
Lana gives Clark counsel and support as he regrets his human-emotion-based decisions. Lana has similar misgivings over her own life and darkness, but Clark also gives her lovingkindness.
At the DP, Lois loses the exclusive on the eclipse phenomenon to another reporter. But the appearance of a breakup with Grant is just that - they still plan to meet that night. Later, Grant claims to Lex that he has broken up with her, but is offended by Lex and his spying on him - now comes the big revelation. What is their secret? Lex is hiding the truth about Grant to protect him from Lionel - he is actually Julian Luthor! Another secret identity is revealed, and calls for much more clarification on this development.
At the Fortress, Clark demands Jor-El's help on finding Kara - but the Voice refuses. Clark's defiance cannot go without consequences. Those will have to come in a future episode, as "Blue" ends with several hanging storylines. It's well-done, maybe even "adventurous," although the emotional impact is slight, partly because Clark lets his human desires overcome his judgment, leading to a threat to the entire planet. The epilog lets him consider his actions, but these second thoughts don't always lead to better decisions in the future. Progress toward destiny is sometimes painfully slow. For production values, script and an interesting concept, "Blue" is above average. Re-run rating C+.