Lana Lang visits an ancient and sick man that has been in prison for more than forty years accused of killing his beloved wife. He shows the picture of the suspect that resembles Clark Kent in an old newspaper and convinces Lana of his innocence. Clark Kent, through flashbacks, revives the passage of Jor-El through Smallville and his affair with the old prisoner's wife, and sees how and who committed the crime.
The successful series "Lost" uses the same presentation of "Relic", i.e., many flashbacks. I did not like this confused episode, since the story is very inconsistent and unfair. The conclusion that Jonathan did not find Clark, but was found by Jor-El indeed is the most relevant event of this episode. My vote is seven.
Title (Brazil): "Relíquia" ("Relic")