It's a birthday party for Clark, with Martha, Lois, and Chloe, but not Lana, and the gifts are pretty sparse. Martha found something Jonathan had bought for Clark, two tickets to a baseball game. Feeling a bit sad over his loss, Clark takes a turn at the cemetery, and Jonathan appears to him again, so John Schneider is still getting some guest spots. He warns Clark again about Lionel, who is going to do something terrible, and insists that Clark must kill him. Tough assignment.
Martha advises caution about the apparition; Clark believes it was real. Lana is back at the Talon, chatting with Lois, and denies that Lex is her boyfriend - Lois is just so up front and unaffected, Lana appears furtive and deceptive by comparison.
Chloe and Clark discuss the ramifications of Lionel knowing Clark's secret. At the mansion, Lionel is aware that Lex is taking another trip to Honduras, smuggling viruses into the US, with Milton Fine's support. Lionel warns Lex to destroy the viruses, and of the danger posed by Fine. John Glover again does some fine acting, he seems to be poisoned and suddenly begins writing Kryptionian symbols as his eyes gray out. Wasn't that the end of last week's episode also? He's channeling someone or some thing, but what?
Chloe and Clark once again easily penetrate Luthorcorp security and rifle Lionels' office for something Chloe amusingly calls "My evil scheme," and hacking into his laptop. They find Lionel's scheduled meeting about a weapon with a Metropolis Inquisitor reporter. I think they're off track, I actually trust Lionel. I believe he's trying to save the world from Lex. When Lana sees Lex, she reports on a good conversation with Lois; Lex is not so sure Lois can be trusted, she being a determined news reporter. Lex decides to reveal more to Lana about Luthorcorp research, is she in 100%? He takes her to a lab, which is pretty well equipped. He describes to her a plan to alter the viruses he's been smuggling in to produce an all-purpose vaccine. Lex still thinks that Fine is a government agent, who is working to defend the world against an alien invasion - the spacecraft being the first of many more. He shows her a photo of the ship in the Honduran jungle. But he has evidence that Fine is an alien. Martha returns Lionel's call; she's suspicious...but then someone is in the house with her - she sees the image of Jonathan, who asks her how long she's had feelings for Lionel. Can a discarnate entity be jealous? She deals rather calmly with this ghostly apparition, and gee, I think it's not Jonathan, it's Mr. shape-shifter himself, still insisting that Lionel has to die. And then he's gone, or rather he's outside, morphing back into Fine!
Martha believed what she saw, telling Clark what Jonathan told her, even that Lionel may have had something to do with Jonathan's death. Surely this will provoke Clark even more. After an unnecessary product placement for AOL on Lex's laptop, FIne strolls right in. So who trusts whom? No one. Here's the deal...Lex has not been telling Fine about the progress of the virus. The vaccine is ready. Lex instead pulls out a meteor rock and tries it on Fine, but it has no effect - he's not a Kryptonian! Then Fine shocks Lex - he reveals what he is by projecting a Terminator-like handsword pointed at Lex, demanding to know the location of the vaccine.
Chloe and Clark begin tracking phone calls from Lionel to Jonathan months earlier, finding that Lionel called shortly before Jonathan suffered his fatal heart attack. Clark is ever more suspicious, and asks Lionel to meet him at the barn. Clark is in a murderous mood, throwing Lionel across the room. Suddenly a Jonathan ghost appears, but Lionel insists that it can't be real - Jonathan would never ask Clark to be a killer. Realizing the truth, Clark turns on the apparition, and there's a violent battle. Then another shock as Lionel manifests superpowers, forcing the Jonathan apparition to return to form as Fine, who disappears. Lionel is back to being himself, but does not realize what happened. Clark now understands the threat posed by Fine, and begins to work with Lionel.
The answers may be in Lionel's little closet of horrors - it's full of notebooks of kryptonian writing, channeled by Lionel. He believes his automatic writing was meant for Clark.
Now they must find the lab where the virus vaccine is being produced. Chloe speculates that someone knows where the lab is - that would be Lana, right? Clark searches Lana's room, as she bursts in, understandably angry at this invasion. Clark asks Lana to trust him, and warns her for the umpteenth time about Lex.
Fine has brought Lex in the lab, and injects Lex with the vaccine. Why? Fine then destroys the lab, in a very impressive fireworks show, as Clark arrives and rescues Lex. All the viruses were destroyed, but where is Fine? In response to Clark's accusations, Lex says Luthorcorp spent $10M producing the vaccine, again implying that he's one of the good guys. Still bitter over Lana turning to Lex, Clark accuses Lex of lurking around waiting for an opportunity to steal Lana from him, but Lex counters, "You lost her all by yourself." Lex has the undisputable advantage in logic about what Lana did. Clark has no argument left.
Lionel stops to see Martha, and to confess. He admits he called Jonathan, then came to tell him he knew about Clark's origins and powers, but Jonathan became so angry that Lionel could not explain his purposes. Lionel has come clean, but this admission still leaves Martha full of unresolved feelings.
Lex and Lana have an evening by the fireside, and Clark is the subject, but Lana wisely asks for a moratorium of the Clark subject. We see that Lex has had a vaccination reaction when he accidently cuts himself, then watches his own finger instantly heal. This miracle he hides from Lana. Wow, what a storyline could be developing here!
After dozens of episodes ending with Lana seeing Clark in the barn loft, it's now Lois visiting him. That's a significant plot shift. It's time for toughlove, she says - Lana needs to move on. Lois is kind and sympathetic, and we can see a good relationship developing there, something we Smallville fans can anticipate. Chloe shows, and he gets lots of good support from her, too. Who would have thought that Superman would need so much moral support and counseling from friends? Another surprise - Chloe has run an analysis program on the symbols - finding several that are repeated, and Clark can read them..."Zod Is Coming." That's a Big "To Be Continued."
This is a "wow" episode, great plot, big surprises, major drama, one of the best of the season, and one that creates great anticipation about what is to come. Re-run rating A.