Difficult episode to review tonight. But I'll give it my best shot. If you don't want spoilers, don't read on. Short Version: Two boys arrive from the stars- one to save, one to destroy. This is the story of the destroyer.
We begin on the day of the meteor shower. While Clark is rescued (sortof) by the Kents, another being, spawned from slime that arrived in an egg-like meteor runs for his life from Luthor security guards. He's no match for them, and is quickly captured.
We transition (through the device of Lionel Luthor's journal) through his brief time with the Luthors, as a playmate for Lex... and his first painful encounter with Kryptonite.
Tess is reading Lionel's journal and learns the truth about Clark and Davis, the two boys from Krypton. She tries to confront Clark and Davis (separately) about this... with varying degrees of non-success.
Davis is, in the meantime, enjoying Chloe's company- because she is the only thing that keeps him from wanting to KILL!KILL!KILL!
But he does anyway, and he buries his victims in the field in Smallville where Clark's ship and Davis' egg landed.
So naturally, Tess blows Davis up.
He gets better.
She tells him that he's Judas to Clark's Christ--- 'where would Christ be and how would he be remembered had not Judas betrayed him?'
So, in an attempt to let this particular cup pass from him, he gets Chloe and Clark to give him a liquid kryptonite bath.
He gets better.
This episode moved me. The abandonment of Davis- the idea that "There but for the Grace of God (or His Instruments, The Kents) go I" was threaded all the way through this episode, turning Davis into a tragic figure (though still a destroyer and a serial killer)
The writers have found Clark Kent's greatest challenge as a character- his ethics prevent him from proactively protecting himself. He does not consider direct threats to his person to be something to wipe out. His goodness prevents him from taking action, mainly because his humility prevents him from considering himself important enough to be protected. This brings up (again, but in probably the most definitive way)Chloe's tendency to protect Clark when he won't do it himself.
And Tess's agenda is for Clark to find his greatness, even if it means betraying him. After all, Judas only pointed the soldiers to Christ; he didn't kill Jesus himself. Tess is the real Judas here, which is ironic, seeing as she perceived that the Luthor Ego prevented Lex and Lionel from seeing that they were not meant to be Kal-El's opposite and equal.
Somehow, Smallville just jumped in the deep end of the pool and decided to swim with Kings for an episode. Oh well, nice to know we're back to light froth next episode.....