S03E06: Relic

Clark discovers that Jor-El was on Earth forty years ago. Lana's great uncle, who was convicted of murdering his wife forty years ago, shows her a picture of the man he believes really killed her aunt, and she is shocked to discover the drifter looks just like Clark. Sure that the man is Jor-El, Clark's investigation leads him to a kryptonian medallion that allows him to see bits of the past - and the life that Jor-El started for him long before he arrived on Earth.