Extinction first aired on 15 October, 2003 and was written by Todd Slavkin and Darren Swimmer. It walks a fine line, introducing a vigilante who is killing meteor-infected people, including Smallville High students.

It’s a fine line, because in the open, Lana (Kristen Kreuk) is saved from a potential stalker and killer, who also had meteor enhanced abilities while she was swimming.

Chloe (Allison Mack) reveals to Clark (Tom Welling) and Pete (Sam Jones III) that she has a list of potential people affected by kryptonite meteors. Clark also resumes his position at the Torch. Clark chases down a lead, connecting a student, Van (Jesse Metcalfe) to the vigilante role.

There’s some real discussion about the infected and how Clark and his friends have been central to a number of incidents. In fact, Van’s mission, to hunt down the infected and execute them, ties directly into established continuity.

Lex (Michael Rosenbaum) and Lionel (John Glover) seem to be getting along well as the pair unite in Metropolis. Lex begins to wonder if there’s something unique about him, he can’t remember being sick. He thinks he may be invulnerable, something to consider how often he’s come close to dying since coming to Smallville. Something that is encouraged when he survives (thanks to Clark) one of Van’s attacks.

And Lionel forces Chloe to realize the real trappings of their agreement.

The series introduces the kryptonite bullet. And Clark isn’t ready for it. It’s a really good sequence!

And if you’re looking for themes in the episode, they are there. Racism is first and foremost.

Slumber sees Clark having some strange dreams, including one that sees him unable to save Sara (Katharine Isabelle). In the dream she is pursued by something called the Traveler (John DeSantis) and Clark is unable to stop it… and the dream started out so well…

In fact, the dream sequence continues past the cold open, with everything but the encounter with Sara and the Traveler (who is draped in a red cloak) being really enjoyable for Clark. Well most of it anyway. As the dream progresses, more and more of Clark’s fears and secrets come home to roost.

Written by Drew Z. Greenberg, the episode debuted on 22 October, 2003. Clark is even more troubled by his dreams when he realizes Sara and her uncle (Christopher Shyer) are the Kent’s new neighbors, and Sara is in a sleep-induced coma, since the day of the meteor-shower.

Can Clark figure out what is going on with Sara, and save her from the Traveler, and possibly her uncle?

Of course, Clark is able to save the day, with some help from Lana.

And meanwhile, Lex and Lionel continue to develop their new business relationship. Which means that Lex has to have a psychological profile done. Is Lionel planning something? Are there some bigger machinations at work here?

A different kind of episode. It’s done well, and we get a fairly basic look at Clark’s internal life.